A fire destroyed the top floor of a bus renovated into a homeless shelter in Brighton last night (January 21).
Jim Deans, founder of Sussex Homeless Support, said it was 'devastating' and that some of those staying on the bus had 'lost everything'.
He said the fire started in a strip light behind lockers on the top floor of the bus. Five people were on the bus at the time but were all uninjured.
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Mr Deans said: "The guys were sitting downstairs eating their dinner. One of the guys went upstairs and said 'I think I can smell a bit of smoke'.
"The smoke alarm went off and two of them went upstairs with the fire extinguishers.
"By that time the smoke was pouring out the side of the lockers.
"The guys downstairs were ringing the fire brigade. They did everything right.
"The fire brigade turned up and put the fire out really quickly."
But he said 'it's going to be weeks' before the bus will be back to normal.
"The upstairs is destroyed really," Mr Deans said. "What is left is smoke damaged and charred.
"There is the water that the fire brigade used to pout the fire out. We have got four inches of water upstairs.
"We have got to rip everything out and start again."
Mr Deans said one man's rucksack was reduced to two metal rods, and a all that was left of a pair of jeans was a belt buckle.
But despite losing everything, he said the attitude of the homeless men staying on the bus was 'let's just fix it'.
He hoped the community would rally round, and said: "We have got so many supporters, so many volunteers. That is the most encouraging thing.
But Mr Deans added: "It could not have happened at a worse time. It was freezing last night, it's going to be freezing tonight."
The charity is set to use its women's bus shelter while the damaged bus is being repaired.
An East Sussex Fire and Rescue Service spokesperson said: "At 8.10pm last night (January 21) two Brighton appliances were sent to Madeira Drive, in Brighton, where they tackled a fire on the top floor of a double decker bus. Firefighters used two breathing apparatus and one hose reel jet to tackle the fire.
"A Positive Pressure Fan was also used to clear smoke.
"An investigation was carried out and the cause found to be accidental."
To find out how you can help the charity, visit: www.facebook.com/groups/sussexhomelesssupport/