Doors were ripped from their hinges and windows smashed in a huge explosion which tore through a former care home in Liversedge on Tuesday.
Thieves stealing copper pipes are being blamed for the blast at the old nursing home in Strawberry Bank at 6.30am.
Doors and windows were blown out and rooms left charred by the explosion at the former Strawberry Bank Care Home.
People living nearby were awoken by the blast, which shook windows and scattered debris up to 30ft.
Lesley Bohanna, who lives opposite, said: “I was asleep when I heard the blast – it shook my windows – and glass flew over into my garden.”
Rachel Hall, who also lives in Strawberry Bank, said: “I heard an almighty bang while I was asleep – it was the loudest thing I’ve ever heard in my life. I went to see what was happening, and we could smell gas.”
John Clayton’s car was damaged by the flying debris.
He said: “A large bang woke us up, so I went out to see what had happened. I was smoking a cigarette at the time and thought ‘I can smell gas here’, so I got away quite quickly!
“I had parked my car in the car park in front of the old care home the previous night, so the flying plastic from the window frames in the building hit my car and caused dents.”
The blast is believed to have been caused by scrap metal thieves stealing gas piping which was still active, and witnesses reported seeing two men in their mid-20s running away from the scene.
Cleckheaton White Watch commander Damian Cameron, who attended the scene, said: “It appears that they have entered the property and stole piping, which has caused a large gas leak which has been ignited.”
Dennis Langham, customer operations manager for Northern Gas works, condemned the thieves, and said that they were lucky to be alive.
He said: “This theft was not only foolish but potentially extremely dangerous. For a few pennies’ worth of metal, these thieves risked their own lives, and put the general public in danger too.
“Their actions were totally reckless and also very unusual, as most people are aware of just how dangerous it is to wilfully damage a gas pipe.
“Fortunately this incident was brought under control quickly and safely by our engineers, but it could easily have had a different, far more tragic ending. Tampering with gas pipes can be fatal. It is never, ever worth the risk.”
A police spokesman said enquiries were ongoing but no arrests had yet been made.
No-one is believed to have been injured in the blast. Anyone with information should contact police on 101.