APOPKA, Fla. -- Investigators have determined the cause of a fire at an assisted living facility in Apopka. Shady Lane Manor, on Orange Blossom Trail, burned to the ground Sunday night.

FIRE SAFETY Story: Fire Deaths By State Tips: For Your Home Tips: Preventing Winter Fires Story: Smoke Alarms Wake Kids? Graph: Plot Escape Routes Quiz: Know How To Escape? Survey: Sprinkler In Every Home? Survey: Is Your Family Prepared?

The fire marshal says a cigarette is what caused the fire. One of the resident was smoking in bed Sunday night.

Owners of Shady Lane Manor are now boarding up the convalescent home. Around 8:30 Sunday night, flames ignited. An elderly woman says she was smoking when, all of a sudden, her mattress caught on fire. Before she knew it, flames engulfed her room and then spread to the living room.

Eleven residents and three workers were evacuated.

Owner Dave Marquez says his mother is devastated by the loss. "She's very upset. This is her sweat, blood and tears. She lives for the elderly people. This is her extended family. This isn't a business, this our life, our family."

Luckily, no one was injured, but the building is a total loss.