Fire and police chiefs said a blaze which caused five people including a baby to escape from a burning block of flats could have been arson.
Firefighters carried the nine-month-old boy down a ladder from the balcony of a first-floor flat during the blaze, before his 21-year-old mother escaped in the same way.
A husband and wife and a a man in other flats were also hauled to safety from the two-storey building on Rutland Close, Clayton-le-Moors at 6pm on Saturday, April 13.
Fire bosses said the fire didn't spread to the flats but a sofa was discovered alight on the first floor landing and was blocking exit routes.
Shona Daffeh, 43, who is disab
She said: "We sat down and I told Papa he must have left the oven on because of all the smoke. He said he didn't and went down the hall and saw smoke pouring in from the other side of the door.
“He shouted to me 'get out'. It was absolutely terrifying. The entire floor was filled with black smoke. You couldn't see your hand in front of your face.
“They had everybody else down but I couldn't get out so they put out the fire and then escorted me out.”
Shona said their flat was badly smoke damaged when they returned home after a night away.
She added: "I am never going to rest easy in this flat again. I'm not safe here and I need to be moved. I have had no sleep since.
“If this had been at night then you wouldn't be asking me any questions because I wouldn't be here.”
Watch Manager Philip Whittaker, of Hyndburn Fire Station, said large quantities of thick black noxious smoke left residents trapped on the upper floor.
He said: "Incidents like this are thankfully rare, but the professional manner of crews from Hyndburn made sure that this serious fire didn’t become a fatal fire."
Paramedics carried out precautionary checks on the rescued people.
Arson has not been ruled out as a cause by Lancashire Fire and Rescue Service.
A joint investigation by the police and the fire service is under way.
A police spokeswoman said the cause of the fire was being treated as unexplained.
She added: “At 6pm on Saturday, April13 police were called by the fire service to a report of a fire in the communal area of flats on Rutland Close in Clayton-le-Moors. The occupants of four flats were evacuated and stayed overnight with friends and relatives. They have since returned home and an investigation is underway into the cause of the fire.”
Anyone with information can contact police on 101.
