An 82-year-old grandfather died in a house fire in Keith Grove, Cleveleys.
Three fire engines were called to the quiet cul-de-sac when neighbours spotted smoke billowing from an upstairs window.
The man, George Wiseman, was trapped inside the home, and six firefighters wearing breathing masks went in to rescue him.
He was found and brought out, but was “sadly pronounced dead at the scene”, Lancashire Police said.
Mr Wiseman’s son Graham, 50, said: “We don’t know what happened yet. We hope he passed away in his sleep.”
Investigators believe the fire may have been started accidentally, and Mr Wiseman said: “He was a heavy smoker.”
Details of Thursday’s fire, which saw three fire crews – one each from Blackpool, Bispham, and Fleetwood – called out at around 3.50am, were only made public this morning when an enquiry was made by the press.
The blaze is thought to have started in an upstairs bedroom, and was put out by firefighters using two water jets as police officers put up a cordon outside.
Mark Jones, 52, of nearby Rookwood Avenue, said: “My wife heard the sirens as we back onto Keith Grove and she woke me up. I didn’t know him personally but it is sad to hear he passed away.”
And Chrissie Walker, 44, of Cresswood Avenue, added: “I used to see him a lot in his garden. He was very friendly and it's such a shame what has happened, a real tragedy.”