Oil Spill Cause

On April 28th, BP issued a brief release:

As an industry, we must participate fully in these investigations and not rest until the causes of this tragedy are known and measures are taken to see that it never happens again.

On April 29th, President Obama made these remarks:

Earlier today, DHS Secretary Napolitano announced that this incident is of national significance and the Department of Interior has announced that they will be sending SWAT teams to the Gulf to inspect all platforms and rigs. And I have ordered the Secretaries of Interior and Homeland Security as well as Administrator Lisa Jackson of the Environmental Protection Agency to visit the site on Friday to ensure that BP and the entire U.S. government is doing everything possible, not just to respond to this incident, but also to determine its cause. And I've been in contact with all the governors of the states that may be affected by this accident.

This was 9 days after the incident occurred and the decision to sweep all rigs in the Gulf and with SWAT teams was far from comforting.

On May 2nd President Obama clarified:

Let me be clear: BP is responsible for this leak; BP will be paying the bill. But as President of the United States, I'm going to spare no effort to respond to this crisis for as long as it continues. And we will spare no resource to clean up whatever damage is caused. And while there will be time to fully investigate what happened on that rig and hold responsible parties accountable, our focus now is on a fully coordinated, relentless response effort to stop the leak and prevent more damage to the Gulf.

All indications are the explosion was an engineering mishap (and timed very close after cement work by Halliburton), but no one believes this to be either an act of war or terrorism.