A family had a lucky escape after a smoke alarm failed to alert them to a fire in their home in St Johns Wood.

Four fire engines and 21 firefighters from West Hampstead and Paddington were called to a maisonette on Abbey Road last night at 7.30pm. No one was injured in the blaze and the fire was under control at 8.15pm.

Due to a flat battery, the smoke alarm failed to go off and it was only thanks to one of the occupants who smelt smoke that the family realised there was a fire.

The fire brigade believe the cause of the fire was smoking materials which had been discarded on some bedding.

A spokesperson for the London fire brigade warned the public of the dangers of having faulty some alarms: “As a minimum you should have smoke alarms on every floor - in the hallways and the rooms you use the most, plus a heat alarm in the kitchen. They should be linked together and tested regularly.”