On Sunday morning, a year ago, Ian Silverstein and his girlfriend, Louise, were woken by an ear-splitting explosion. They were under a pile of brickwork, dust, plaster and broken glass. Through the hole where their bedroom window had been came the searing heat of the biggest fire seen in Europe since the war.
Three hundred tons of unleaded petrol that had leaked from a tank at the Buncefield oil depot in Hemel Hempstead, Hertfordshire, had exploded. Experts are still puzzling over how even that volume of petrol vapour could have produced an explosion so powerful that buildings 2km away were severely damaged. The air pressure in the area of about 80,000 square metres around the explosion must have doubled, creating conditions like being inside a hot, inflated car tyre.
Three huge office buildings, including the national headquarters of Northgate Information Solutions, were completely destroyed. The head office of another IT firm, Steria, was protected by being half a mile away in a dip and screened by buildings, yet it suffered hundreds of thousands of pounds of damage. Three office workers monitoring its computers were blown off their chairs. Amazingly, the firm continued operating as normal the next day.
Mr Silverstein was told by the Meteorological Office that the side of his house was hit by a force measuring 4.3 on the Richter scale. Bleeding from head injuries that later required eight stitches, Mr Silverstein and his girlfriend ran through the debris of their home, and out into the yard.
The roof of an outhouse that Mr Silverstein used as a garage had fallen in, wrecking the car, but to the couple's relief the engine started. As they sped down their long drive, dodging the branches ripped from trees, they spotted their neighbours Barry Phillips and Karen Kucper, and four terrified girls in their nightclothes.
Ms Kucper's 13-year-old daughter, Milly, had had three friends to stay for a sleepover. Their house had also been destroyed. "I just felt so awful because I was supposed to be looking after them," Ms Kucper said.
"Our bedroom door was held on by the bottom hinges, so we had to clamber over that to get to their bedroom, which was covered in shattered glass where the window had blown in. The door was balancing on the bed."
They bundled the weeping girls into Mr Silverstein's car and set off on foot in a terrifying flight for their lives along an unlit lane. They assumed that their near neighbours, an elderly couple who lived even closer to the depot, must be dead. The explosion had removed the top of their house, but fortunately they slept downstairs.
The parents of one of the girls, who needed hospital treatment for cuts, bought her a new pair of shoes to replace the ones lost in the wreckage. They cost £17. Their solicitor, Des Collins, who has been handling more than 200 claims arising from the fire, forwarded the bill to Hertfordshire Oil Storage, which owns Buncefield. To his astonishment, the company's loss adjusters quibbled with the bill, claiming that since the lost shoes were not new, they would only pay £12 towards the replacements.
"We were arguing over £5, but how long can you keep arguing?" Mr Collins said.
These people will never return to live in their own homes, which were wrecked beyond repair. They were not allowed to see the damage for several days, because the police had closed off all lanes leading to the fire as it continued burning.
Mr Silverstein, who runs a design business, believes his house was worth £1.3m on the eve of the fire. By the next morning, it was a worthless wreck that now has the musty smell of a disused building, although among the clutter there is evidence of what was an expensively furnished home.
His insurance policy, like that of most householders, only covered the "replacement" of the house, not its market value. He was paid £450,000, which he had to pass straight on to his mortgage lenders. Several thousand pounds worth of DVD equipment and other expensive goods were looted.
On Monday, the first anniversary of the explosion, there will be a thanksgiving service in Hemel Hempstead, marking the extraordinary fact that although 43 people were injured, no one was killed. But the trauma of Buncefield is not over for many of its victims, and there are still unanswered questions.
Mike Penning, Hemel Hempstead's MP, said: "We know how it went bang but we don't know why. We don't know why the Health and Safety Executive, who were inspecting the site, passed it as safe. We don't know why the firefighting tanker had not been used for so long that its brakes had seized up. There are hundreds of these depots around the country. Public confidence needs to be restored - and not just in my constituency."
Buncefield by numbers
9,000ft the height of the plume of smoke created by the fire at Buncefield. It could be seen from space
2,000 people had to be removed from homes in the area
43 people were injured
100 miles the distance from which the force of the explosion could be heard
60 million gallons of fuel, from 20 petrol tanks, were involved in the explosion
32 hours length of time the inferno took to put out
150 firefighters from 17 brigades were deployed to tackle the blaze, described as the biggest of its kind in peacetime Europe
200 schools in a 10-mile radius had to close for two days because of concerns for the health of the children
350 people asked for help after being left temporarily homeless, according to a local charityReuse content