Chlorine gas attacks in Douma, Syria
Image and spatial analysis of claims surrounding alleged use of chemical weapons in April 2018
In collaboration with the New York Times
On 7 April 2018, the Syrian city of Douma was allegedly targeted by two chemical weapons attacks. At that time, the city and its surrounding areas had been under siege by the Syrian military since 2013. At least 70 people died in the attacks, according to reports.
Two distinctive yellow canisters, similar to those previously linked to chlorine gas attacks across Syria, were found following the strikes: one on a rooftop balcony near to Al Shuhada square, and the other in a bedroom at an unknown location in the city.
Days later, following the negotiated surrender of the remaining rebel forces in Douma, Russian media were the first to be allowed access to the attack sites. Reporters from RT and TV Zvezda quickly claimed that the attacks had been staged. Both claimed that the canisters found at each location had been carried into place by the rebels, rather than dropped from regime-controlled airspace above the city.
Commissioned by and working closely with the New York Times, Forensic Architecture searched for physical evidence concerning how the canisters had arrived at each scene. We reconstructed the two sites as 3D models using available images and video material. We also reconstructed the canisters as digital objects and analysed the physical traces inscribed on them.
Our analysis supports the assessment that the canisters were dropped from the air. At both sites, we identified a metal harness used to transport the canister, consistent with the aerial delivery of munitions documented elsewhere in Syria. Image and sound analysis revealed further evidence at each site.
We used open-source software called Blender to build 3D models of the attack sites and the canisters themselves. The dimensions of each 3D model were established from satellite imagery and corroborated by architectural details in images captured at ground level.
In order to reconstruct the canisters’ exterior surfaces, we projected multiple images from different angles onto a cylindrical surface. In doing so, we took into account variations in the position and focal length of different cameras, and corroborated details on the canisters’ surfaces across multiple images.
Forensic Architecture team
- Eyal Weizman (principal investigator)
- Nick Masterton (project coordinator)
- Bob Trafford
- Grace Quah
- Ariel Caine
- Stefan Laxness
One Building, One Bomb: How Assad Gassed His Own People | New York Times, 24 June 2018
How we created a virtual crime scene to investigate Syria’s chemical attack | New York Times, 24 June 2018