Timeline for Gulf of Mexico oil-spill disaster

APRIL 20
Explosion on BP's Deepwater Horizon rig off the Louisiana coast: 11 workers killed. Two days later the rig sinks creating a 8km slick. A week later the US Coast Guard estimates 5000 barrels a day leaking.

MAY 2
US President Barack Obama visits the affected areas vowing BP will pay. BP chief Tony Hayward says company will pay for the clean-up. Work begins on drilling a relief well.

MAY 7
First attempt to plug the leaking well with a 100-tonne concrete cap fails. Two days later it attempts a "junk shot" - rubbish including golf balls, tyres and mud - to stem the leak.

MAY 11
Congressional hearing told explosion the result of a "cascade of errors". Obama criticises "ridiculous spectacle" of oil industry officials blaming each other.

MAY 20
First heavy oil reaches Louisiana. Experts concerned ocean currents could bring a slick the size of Luxembourg to the coast. Government triples size of the area of the Gulf of Mexico that is off-limits to fishing boats.

MAY 26
BP starts Operation Top Kill to choke off the leak. It fails three days later. The next day Obama extends the deepwater drilling ban for a further six months.

JUNE 1
BP shares fall 17 per cent as US announces criminal and civil investigations.

JUNE 4-7
BP place a cap on the well. Eric Holder, the US Attorney-General, announces he is to visit the site of the spill, increasing speculation that a criminal investigation is in prospect.

JUNE 8
Obama says of BP's chief executive Tony Hayward: "If he worked for me I'd sack him." The comment and others prompt concern in Britain about increasingly vehement attacks on the company.

JUNE 11
Admiral Thad Allen writes to BP's chairman for first face-to-face summit as concern mounts about "anti-British sentiment" in attacks on BP. By this time the estimate on the leak has soared to some 40,000 barrels a day.

JUNE 12
British Prime Minister David Cameron warns Obama not to undermine BP's economic value. Downing Street stresses the special relationship has not been undermined by the catastrophe.

- INDEPENDENT