LONDON, ONT. -- London fire officials are crediting working smoke alarms for possibly saving a woman’s life after a fire in a multi-unit dwelling east of downtown.

Fire crews were called to the 600-block of King Street just east of Adelaide St. around 10 p.m. for reports of a fire within a unit.

Officials tell CTV News that a mattress had caught fire while the female resident was asleep.

A working smoke alarm woke the woman who was able to escape.

She was assessed on scene and taken to hospital to be observed for possible smoke inhalation.

Fire officials say the smoke alarm may have saved her life.

Damage from the fire is estimated to be $30,000.

The London Fire Department wishes to remind the public to never smoke in bed.