Over the past two weeks, the Coast Guard has held hearings on how the Titan, a privately owned submersible vessel that imploded 15 months ago at the bottom of the North Atlantic Ocean, resulted in the deaths of the five people inside.

The Coast Guard has posted videos of Titan wreckage two miles beneath the water’s surface, as well as a detailed log of communications between the craft and its mother ship, scores of documents, and the recorded testimony of more than two dozen witnesses, including former employees of the sub’s maker, OceanGate.