Oil platform explosion in the Gulf of Mexico

Boats spray water on an oil platform after it exploded in the Gulf of Mexico on 2 September 2010 off the coast of Louisiana. The 13 crew members were rescued and some were being treated in a Louisiana hospital Photograph: Mario Tama/Getty Images

Boats are seen spraying water on the oil and gas platform that exploded Photograph: Gerald Herbert/AP

Boats continue to extinguish the fire Photograph: Gerald Herbert/AP

Ariel view of boats as they spray water on the oil platform Photograph: Mario Tama/Getty Images

An unidentified substance is seen on the water near the explosion on 2 September 2010. Although the coast guard claimed that there was no sign of an oil leak, there were other reports of a sheen visible on the water Photograph: Mario Tama/Getty Images

In this image courtesy of KATC3 news channel in Lafayette, Louisiana, the offshore oil platform burns 100 miles south of the Louisiana coast Photograph: AFP/Getty Images

In this image courtesy of KATC3 news channel, the 13 workers wait for rescue after they jumped into the sea Photograph: AFP/Getty Images

A person believed to be survivor of the explosion is helped off a coast guard rescue helicopter on the heliport of Terrebonne General Hospital, where injured and survivors were taken, in Houma , Louisiana Photograph: Gerald Herbert/AP

Captain Peter Troedsson, chief of staff for the Eight Coast Guard District, holds a press conference at the Hale Boggs Federal Courthouse, Poydras Street, New Orleans to discuss the incident Photograph: Matt Davis/AFP/Getty Images

Two rescued workers, left, walk away from a US coast guard helicopter on the roof of Terrebonne General Medical Centre Photograph: Patrick Semansky/AP