Residents faced a midnight evacuation from their homes after a guesthouse was engulfed by flames.
Around 30 firefighters from across the Fylde coast and Preston were called to the three-storey property, in Palatine Road, central Blackpool, as flames reached into the dark night sky.
Residents reported hearing an explosion, while floors and stairs inside the property — believed to have been undergoing renovation work — also collapsed.
The blaze started on the ground floor and rapidly spread upwards, bursting out through the roof and spreading into an empty property next door.
Jonathan Leese, a 35-year-old security guard, was walking home with colleagues Chris Lawson and Helen Ashby when he saw a ‘flash’ followed by a loud ‘bang’ from inside the guesthouse at around 11.10pm yesterday.
He said: “We got literally three metres away and from the corner of my eye I just saw a flash of light.
“It lit up the whole of the downstairs.
“There was a massive bang and the concrete supports from the bay window flew out towards us.
“We had to leap out the way.”
Mr Leese, who works at Tesco Express in Central Drive and lives in Ascot Road, described a strong smell of gas, and said a neighbour burst out of a nearby house and told him the back of the property was engulfed by flames.
Mr Leese dialled 999 and began banging on doors, trying to alert people to the danger.
By the time emergency services arrived, the building was already an inferno.
Five fire engines, from Blackpool, South Shore, Bispham, and St Annes stations, and an aerial ladder platform and crew from Preston, attended.
Residents were evacuated, with some woken from their beds, while the road was closed.
A car parked over a fire hydrant had a window smashed so firefighters could release the handbrake and move it out of the way, a spokesman for Lancashire Fire and Rescue Service said.
“A number of water jets were set up and firefighters were equipped with breathing apparatus to get into close proximity to the fire, which had made the interior largely unaccessible, having burnt through floors and stairs,” he said.
“Information had been passed to firefighters that the property was under renovation but, although no-one was expected to be in the building, firefighters ensured that no-one was trapped inside and there were no casualties.
“The two neighbouring properties on either side were unoccupied but firefighters asked police to evacuate home further down the terrace as a precaution.
“The fire spread to one adjoining property at roof level, but this was quickly extinguished with the use of the aerial ladder platform-mounted water jet directed at it from height.”
IT designer Andy Watts, 43, of Leamington Road, was driving past the scene when he saw Mr Leese and his colleagues banging on neighbours’ doors.
He live streamed the drama for 45 minutes and today told The Gazette: “There was such a horrible smell. It was a funky chemical smell; a strange, weird smell.
“There were around 30 people stood out, some were dressed and others just had jogging bottoms on.
“They were just bewildered by it. It was a bit of an experience.”
The flames were out by dawn, although the road was expected to remain closed for several hours while an investigation is carried out.
Fire crews will remain at the blackened shell of a building for most of the day, gathering forensic evidence and speaking to witnesses.
A spokeswoman for Lancashire Police said officers were helping with the investigation.