On 7 April 2018, the city of Douma, Syria, was 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. 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. -FA