But how did the 147,000 tonne supertanker come to be off course on her way into Britain's busiest mainland oil port, in moderate conditions, when shipping safety is supposedly vigilantly policed? And why have the Anglo-Dutch salvagers failed to free her?
The disaster struck between 8.07 and 8.20 last Thursday night. The Liberian- registered tanker was heading into Milford Haven in Pembrokeshire, aiming for the Texaco oil refinery. A pilot boarded to help guide her on the last lap of her journey. But within 15 minutes of him boarding she hit a sandbank and rocks in the waters around St Ann's Head. The vessel, carrying 140,000 tonnes of crude oil, was one-quarter of a mile inside the outer Channel marking as water gushed in and she began to sink.
Captain Eduard Bolgov, head of the 28-strong Russian crew, was on the bridge. But he had handed over control to the pilot by the time water swept across the tanker, equivalent in size to three football pitches. He described afterwards how they experienced " a great shuddering" as the ship went through the entrance to the outer harbour.
It was not just a shipping disaster, in exactly the same waters where a vessel ran into trouble three-and-a-half months ago. For the surrounding waters and shoreline, Britain's only coastal national park which boasts some of the finest marine life in Europe, the Sea Empress was a ecological time bomb. Already thousands of tonnes of oil were gushing from the damaged tanks to form a three-mile slick.
Government officials, from the coastguard, port authorities and marine- pollution unit, were mobilised immediately. Their first task was to establish a salvage team, and evacuate anyone in danger both on the vessel and on shore. There were fears of a gas explosion on the ship.
By Friday the winds had whipped up a five-mile oil slick. Environmentalists hoped that the direction of the wind meant the oil would not be carried towards the coastline, home to 500,000 sea birds, colonies of grey seals and communities of rare shellfish.
The marine pollution unit sent seven DC Decota aircraft fitted with spray equipment to drop chemical dispersants. It also oversaw the installation of protective booms in front of marshlands. The technique was perfected in Kuwait during the Gulf war when Iraqi troops threatened to manipulate an environmental disaster.
Coastguards declared the tanker disaster a full-scale emergency. Their priority was to move the vessel to a position where she could be secured, so that her potentially lethal cargo could be pumped off onto a smaller ship.
But the elements have frustrated the salvage operation from the outset. "We've seen the Sea Empress run aground three times in four days," a St Ann's lighthouse keeper, who wished to be anonymous, said. "That ship's got a mind of her own, she's not doing what anyone wants her to do."
Two teams of Dutch divers assessed the damage to the tanker's pump room and 17 cargo tanks. Meanwhile, four tugs kept her in position off St. Ann's Head, at the entrance to Milford Haven, intending to bring the 30,000 tonne Star Bergen alongside to take off the oil.
But by Saturday morning it was clear that the winds were intensifying and dramatic gale force winds were forecast. The salvagers decided to turn the ship around so her bow was facing out into the gathering storm.
But at 6.30pm when the storm struck, two of the tugs holding her lost their tow lines and the stern swung back round. Two other tugs held on, but the supertanker's anchor chains snapped and it was all they could do to stop her going out of control.
On Sunday the salvage experts were dropped on board by an Royal Air Force Sea King helicopter - they were still hopeful that the vessel was salvagable. Despite the ship's heavy list, the engine room was not flooded. Yet by the evening the operation had collapsed again, and had almost descended into farce.
A 21,000hp Chinese tug, the seventh most powerful in the world, had managed to get a tow line to the ship, which was sill threatening to drift out of control. However, the captain spoke only Cantonese, while the British pilot on board spoke only English. The coastguards called the local Happy Garden Chinese takeaway out of desperation, and Paul Chung, the chef, was called to the port at 10pm to translate. The Chinese tug was later put to one side "on stand by".
On Monday, the authorities allowed themselves a further display of optimism. But once again their hopes were dashed by the weather.
The 21-strong salvage crew on board the Sea Empress attempting to get the supertanker's systems running again were driven off at 11.45pm by more gale-force winds, and the supertanker drifted one-quarter of a mile along the coast in the highest tide of the month before coming to rest beside the cliffs.
It was, according to the rescue officials, "disappointing".
The salvage team announced that they were bringing forward their plans to move the vessel to a secure mooring by two days to last night, so pumping could begin immediately.
Stephen Dennison, director of Cory Tugs, one of the three companies involved in the salvage operation, insisted: "You ultimately cannot fight against the weather."
But visitors, who had gathered at St Ann's Head to watch the spectacle, were growing increasingly sceptical yesterday.
"Why wasn't something done? We can't understand how it came to this. We've been coming here on holiday for 20 years and it's one of the most beautiful parts of Wales," Nick Roberts, a teacher from Cardiff, said.Reuse content