After BP’s internal investigation, the fatal explosion on the oil rig in the Gulf of Mexico was said to be triggered by a bubble of methane gas that escaped through the well and shot up the column before exploding.

The cause of the explosion is still being investigated, but BP investigators interviewed rig workers to get a detailed account of what happened the day that the rig exploded, killing 11 workers. Investigators are focusing on what is called the blow-out preventer to make sure that they are reliable on rigs.

Gas explosions can cause serious injury and death and the aftermath is devastating to all involved. Our thoughts are with the families of the victims.