3D mapping explained: Why Delhi cops plan to use it to solve Vivek Vihar fire tragedy

According to an officer, a draftsman, who is part of the crime team that visits the spot after an incident, takes measurements in a notebook. Later, with the help of drafting equipment and AutoCAD — a computer-aided design software — a map of the crime scene is prepared.

How will this help?

In the Vivek Vihar case, an officer said that it can help provide details such as the floor and the location where the fire may have started in the multi-storey building. It can also provide possible details about objects and obstacles present in the room during the fire.

The technology helps map burn patterns, collapsed structures, stairways, windows, wiring, gas cylinders, AC or gas pipelines, making the fire’s progression easier to reconstruct. It can also help in establishing illegal construction.

How is 3D mapping different from the 2D method?

2D mapping records only length and breadth — essentially a flat layout of the scene.

Police usually rely on 2D mapping in heinous or complex cases to present a clear graphical representation of the crime scene and location on paper. This work is carried out by the draftsman.

3D mapping, on the other hand, adds height to that reconstruction. This additional dimension helps investigators understand how events may have spread across floors, which is crucial in cases like sniper shootings, incidents involving a person falling from a height, such as a building or terrace, or fires in multi-storey buildings.

Before the advent of this technology, Delhi Police officers used to draw maps from scratch by hand after taking measurements at the site.

Has this technology been used before?

Yes. A similar 3D reconstruction was used in the 2019 Anaj Mandi fire in central Delhi, where 43 workers died. In that case, investigators used the technology to create a detailed panoramic view of the building’s interior and exterior, helping reconstruct how the tragedy unfolded.

What do investigators know so far about the Vivek Vihar fire?

According to a senior officer, the rear portion of the four-storey building was the most affected, with casualties reported among residents living on the second, third, and fourth floors. Families living in flats on the front side of the building, however, managed to escape.

The building, located in B Block of Vivek Vihar, has a parking space on the ground floor and two four-bedroom flats, both on the front and rear side on each of the other floors. It was built in 2017 on an 800-square-yard plot.

Preliminary findings suggest the fire may have been triggered by a short circuit on the second floor, but investigators are still trying to identify the exact source — whether it was an appliance like an air conditioner, an electrical board, or a meter box.