A discarded cigarette is believed to have caused a blaze in a block of flats.
The used cigarette is believed to have set fire to a mattress and plastic toys on the second floor landing of the flats in South Street, in Ponders End late on Friday, July 18.
The blaze affected the second floor stairwell.
Crews gave residents living in the block fire survival guidance.
A London Fire Brigade spokesperson said: “Living in a flat is not more dangerous than living in a house, but it’s important to know that your fire plan should be different. Flats and maisonettes are built to give you some protection from fire – a minimum of 30 minutes and up to 60.
“Walls, floors and doors will hold back flames and smoke for a time. If there is a fire elsewhere in the building but not inside your home you're usually safer staying in your flat unless heat or smoke is affecting you.”
“If you leave your flat you could be rushing into choking smoke, the fire itself or firefighters using equipment to bring the fire under control in another part of the building.
“This fire started after a mattress on a landing caught fire. It’s important to make sure halls and exits are kept clear of items like this as not only can they pose a fire risk, they can prevent your escape route if there is a fire.
“We believe the fire was started accidently by a discarded cigarette. It’s vital you fully extinguish cigarettes before discarding them.”
Ten firefighters tackled the blaze from 5.09pm. It was under control at 6.51pm.