Video footage released by the US Coast Guard shows the moment the wife of the late OceanGate CEO Stockton Rush heard the apparent sound of the Titan submersible imploding. In the video, Wendy Rush, a director at the ocean tourism company — which has since suspended all operations — can be seen attempting to contact the sub from the Polar Prince support vessel when a loud slamming sound can be heard through her monitor.

The documentary also reveals the carbon fibre used to build the submersible started to break apart a year before the fatal dive.