Transocean Ltd. provided an update regarding a fire and explosion onboard its semisubmersible drilling rig Deepwater Horizon and reports that the rig sank late in the morning, today.

The combined response team was not able to stem the flow of hydrocarbons prior to the rig sinking, and we are working closely with BP Exploration & Production, Inc. and the U.S. Coast Guard to determine the impact from the sinking of the rig and the plans going forward. The U.S. Coast Guard has plans in place to mitigate any environmental impact from this situation.

The incident occurred April 20, 2010 at approximately 10:00 p.m. Central Time in the United States Gulf of Mexico. The rig was located approximately 41 miles offshore Louisiana on Mississippi Canyon block 252.

The cause of the fire and explosion is unknown at this time. An investigation into the cause of the incident and assessment of the damage will be ongoing in the days or weeks to come.

Tags: Transocean Inc.