Fire crews say functioning smoke alarms likely prevented a tragedy at a London apartment building early Sunday.

Multiple units responded just after 2 a.m. to a report of smoke in the basement of a complex on Emery Street West. They arrived to find heavy smoke in both the hallway and the affected unit, eventually tracing the source to a stovetop hazard.

London Fire later noted that the unit’s working smoke alarms may have saved the occupants’ lives and urged residents to ensure their homes are equipped with properly functioning alarms.