The Science of Blast Analysis: Investigating the Red Fort Explosion

A City Shaken: Deconstructing the Science Behind the Red Fort Blast Investigation

In the heart of Delhi, a city that beats with the rhythm of millions, the evening of November 10, 2025, was shattered by a deafening roar. Near the historic Red Fort, a symbol of India's rich past and vibrant present, a car exploded amidst the dense rush-hour traffic. The blast, which occurred around 6:52 PM on Subhash Marg, was not just an act of violence; it was a complex puzzle thrown at the feet of India's premier investigative and scientific bodies. The explosion, originating from a white Hyundai i20, claimed the lives of at least 13 people and injured over 20 others, turning a mundane evening into a scene of carnage and chaos.

As the smoke cleared and the immediate, heroic efforts of first responders gave way to the meticulous process of investigation, it became clear that this was no ordinary incident. The case was quickly handed over to the National Investigation Agency (NIA), India's top counter-terrorism task force, signaling that the authorities were treating this as a deliberate act of terror. Working in tandem, the NIA, the National Security Guard (NSG), and the Forensic Science Laboratory (FSL) began the painstaking task of piecing together the evidence. What they found—and what they didn't find—has opened a fascinating window into the sophisticated world of modern blast analysis. The investigation into the Red Fort explosion is a compelling case study in the application of physics, chemistry, and biology to unravel the secrets of a catastrophic event.

The Immediate Aftermath: The Crime Scene as a Scientific Canvas

The first principle of any post-blast investigation is that the crime scene itself is the most critical piece of evidence. Every fragment of debris, every scorch mark, every shattered piece of glass tells a part of the story of the explosion's anatomy. Investigators approached the chaotic scene on Subhash Marg not just as a site of tragedy, but as a vast, open-air laboratory.

The initial moments are a frantic but systematic ballet of securing the perimeter, documenting the scene, and identifying and preserving evidence. The primary goals are to understand the "what, where, who, why, and how" of the blast. The "where" is the seat of the explosion, its epicenter. In the case of the Red Fort blast, it was quickly identified as the Hyundai i20. The vehicle, or what was left of it, became the focal point.

One of the most perplexing early findings was the absence of a crater on the road surface. High-explosive detonations typically release energy at supersonic speeds, creating a powerful shockwave that displaces material and gouges a crater into the ground. The lack of one at the Red Fort site was a significant clue, suggesting something other than a conventional, high-order explosion. An official from the FSL noted, “If a conventional explosive or an improvised device had been used, some trace — like pitting on the road surface or fragments — would have been evident.” This led to initial, and quickly dismissed, theories of a CNG cylinder explosion. However, the sheer destructive force, which gutted multiple vehicles and flung debris over considerable distances, was inconsistent with a contained gas-tank failure.

Another puzzling absence was the lack of typical shrapnel, such as nails, ball bearings, or even significant metallic fragments from a bomb casing. Terrorist devices are often packed with such items to maximize casualties. Their absence suggested either a different motive or a different type of device altogether—perhaps one where the blast and thermal effects were the primary goal, or a device that was, as some sources suggested, "premature and not fully developed."

Forensic teams methodically collected evidence, using techniques like the Trace Explosives Recovery Kit (TERK), which can gather residues as small as one billionth of a gram. Every piece of the mangled Hyundai i20, samples of soot from nearby buildings, and debris from the surrounding area were carefully cataloged for laboratory analysis. This collection is vital because even after a powerful blast, unconsumed explosive material and characteristic chemical byproducts can cling to surfaces, providing a chemical fingerprint of the bomb.

The Laboratory Deciphers: Chemistry and Physics of the Blast

With the evidence secured, the focus shifted to the laboratories of the FSL. Here, scientists employ a battery of sophisticated techniques to answer the most pressing questions: What was the explosive material? How was it detonated?

Identifying the Explosive Heart

Initial suspicions, based on intelligence and a related explosives seizure in Faridabad, pointed towards the use of ammonium nitrate. Ammonium nitrate is a common fertilizer that, when mixed with a fuel source like fuel oil (a combination known as ANFO), becomes a powerful, though relatively stable, high explosive. It has been a component in numerous terrorist attacks globally due to its accessibility.

To confirm this, forensic chemists analyze the collected residues using a variety of instrumental techniques:

Ion Chromatography (IC): This method is particularly effective for identifying inorganic explosives like ammonium nitrate. The collected debris is washed with a solvent, and the resulting liquid is injected into the IC. The machine separates the different ions present in the sample, and detectors can identify the characteristic nitrate (NO₃⁻) and ammonium (NH₄⁺) ions.
Gas Chromatography-Mass Spectrometry (GC-MS): This is a workhorse in forensic chemistry. It is used to detect organic explosives (like TNT or RDX, which one source suggested could have been mixed with the ammonium nitrate) and can also identify the fuel component in an ANFO mixture. The GC separates the complex mixture into individual components, and the MS bombards them with electrons, breaking them into predictable fragment patterns, which act like a chemical fingerprint.
Infrared Spectroscopy (FTIR): This technique shines infrared light on a sample. Different chemical bonds absorb the light at specific frequencies, creating a unique spectrum that can be matched against a library of known substances, including explosives.

These tests are painstaking. Post-blast samples are often a messy cocktail of burnt materials, soil, and tiny amounts of the explosive itself, all of which can contaminate the evidence. However, identifying the explosive is crucial; it provides investigative leads, pointing towards the bomb-maker's methods and potential sources of the materials.

High-Order vs. Low-Order: The Meaning of the "Fireball"

The visual and physical evidence at the scene—a massive fireball but no crater—points to a critical distinction in blast analysis: the difference between a detonation and a deflagration.

A detonation is a characteristic of high explosives (like TNT or C-4). The chemical reaction travels through the explosive material faster than the speed of sound, creating an instantaneous and incredibly powerful shockwave. This is a shattering effect, which is what carves out craters and pulverizes bomb casings into tiny fragments.

A deflagration, on the other hand, is a subsonic combustion, essentially a very rapid burn. This is typical of low explosives, like gunpowder. The energy release creates a pushing or heaving effect, rather than a shattering one. This results in a large fireball and can still be incredibly destructive, but it is less likely to create a classic crater.

In the Red Fort case, reports suggested the bomb might have been "premature and not fully developed." This could indicate a "low-order" explosion. A low-order explosion occurs when a high explosive fails to detonate properly and instead deflagrates. This can happen due to an inadequate initiator, instability of the chemical mixture, or poor design. The result is an incomplete consumption of the explosive material and a less efficient energy release, characterized more by a fiery push than a supersonic shock. This would align perfectly with the evidence observed: a massive fire that engulfed nearby vehicles and the absence of a significant crater or widespread shrapnel. The explosive, while still tragically lethal, did not achieve its full destructive potential.

Reconstructing the Device: The Ghost in the Machine

Beyond the chemical nature of the explosive, investigators must reconstruct the device itself. An Improvised Explosive Device (IED) has four key components: a power source (like a battery), an initiator (like a blasting cap), a switch (the trigger), and the main charge (the explosive). Finding fragments of these components is like finding the bomb-maker's signature.

Investigators at the Red Fort site were looking for remnants of wires, circuit boards, batteries, or any non-explosive components. The absence of such findings in initial reports was another puzzle. This could mean the components were either completely vaporized in the blast—less likely in a low-order event—or that the triggering mechanism was something less conventional.

The investigation is also leveraging digital forensics. Authorities are analyzing data from cell towers to identify all mobile phones that were active near the Red Fort at the time of the explosion. This could reveal a remotely detonated device triggered by a phone call or text message, a common tactic in modern terrorism.

Furthermore, the investigation is relying heavily on Computational Fluid Dynamics (CFD). CFD is a powerful simulation tool that uses computers to model the flow of gases and the propagation of a blast wave. By inputting the known variables—the type of vehicle, the suspected amount and type of explosive, the surrounding buildings, and the resulting damage patterns—investigators can run virtual reconstructions of the explosion. These models can help:

Pinpoint the Origin: By comparing the simulated damage to the actual damage, they can refine the exact location of the bomb within the vehicle.
Estimate the Yield: The simulations can help estimate the quantity of explosives used by matching the blast effects to a known TNT equivalency.
Validate Theories: They can test hypotheses, such as the effects of a low-order versus a high-order explosion, and see which one better matches the real-world evidence, like the lack of a crater and the specific damage to nearby vehicles and the metro station.

The Human Element: DNA as the Ultimate Identifier

Perhaps the most somber and critical task in the aftermath of the blast is identifying the victims, including the potential perpetrators inside the vehicle. The intense heat and force of an explosion can leave bodies severely fragmented and burned, making visual identification impossible. In these situations, forensic biology and DNA analysis become the gold standard.

The investigation quickly zeroed in on a suspect, a doctor from Pulwama, believed to have been driving the car. To confirm his identity, a grim but necessary process was initiated. Forensic specialists collected biological samples—such as bone fragments or deep muscle tissue—from the charred remains found in the driver's seat. Simultaneously, authorities in Jammu and Kashmir collected a DNA sample from the suspect's mother.

The process of DNA identification from such compromised samples is a marvel of modern science, often borrowing techniques from the study of ancient DNA:

Extraction: DNA is extracted from the collected tissue. Dense bone and teeth are often the best sources, as they can protect the DNA from the extreme heat of a blast better than soft tissues. The bone is ground into a fine powder to maximize the surface area for chemical extraction.
Quantification: Scientists determine how much human DNA, if any, was recovered. This is a critical step, as the samples can be heavily degraded or contaminated.
Amplification: Using Polymerase Chain Reaction (PCR), specific segments of the DNA known as Short Tandem Repeats (STRs) are targeted and copied millions of times. Forensic science uses a standard set of 20 STR markers for human identification in the U.S., with similar standards used worldwide.
Profiling and Comparison: The amplified STR markers are analyzed to create a unique genetic profile. This profile is then compared to the DNA from the suspect's mother. Since a child inherits half of their DNA from their mother, a direct biological relationship can be definitively established or refuted by comparing the profiles.

This same process is applied to identify all the victims of the tragedy, providing crucial answers to their grieving families. Even from the most chaotic and destructive scenes, the unyielding science of genetics can provide a name to the nameless and bring a measure of certainty to an uncertain world.

The Broader Context: A Planned Attack Gone Awry?

The scientific investigation does not happen in a vacuum. It is intricately linked to the intelligence and police work running in parallel. The Red Fort explosion appears to be connected to the busting of a major terror module in Faridabad just hours earlier, where a massive cache of nearly 2,900 kg of explosives, including ammonium nitrate, was discovered.

Sources within the investigation have theorized that the blast may have been triggered in panic. The driver, realizing that the terror network was being dismantled and that his arrest was imminent, may have attempted to detonate the device hastily, either to destroy evidence or in a desperate final act. This "panic theory" is strongly supported by the scientific evidence of a premature or low-order explosion. An improperly armed or unstable IED could have been triggered accidentally by the motion of the vehicle or by a nervous handler, leading to an incomplete but still devastating blast.

The science of blast analysis is a multidisciplinary symphony of observation, chemistry, physics, and biology. The investigation into the Red Fort explosion is a testament to the power of these scientific principles. From the initial search for clues in the debris to the complex chemical analysis in the lab, the genetic identification of victims, and the virtual reconstruction of the event on a supercomputer, every step is guided by the scientific method.

While the human tragedy of the event is immeasurable, the scientific response provides hope. It offers a path to understanding the unthinkable, to holding the perpetrators accountable, and to learning lessons that may prevent future atrocities. The shattered streets near the Red Fort are not just a crime scene; they are a complex scientific problem, and in solving it, investigators seek to restore a semblance of order and justice to a world violently disrupted.