ON April 20, a drilling rig in the Gulf of Mexico exploded. The rig was called Deepwater Horizon, well named for British Petroleum's (B.P.) remarkable effort to draw oil from a deep-sea rig that has to go through 22,000 to 25,000 feet (6,600-7,500 metres) of water before it strikes the seabed.

Eleven oil workers are presumed dead although their bodies have not been found.