A 56-year-old woman was found dead early Monday after a fire at her home in northwest suburban Island Lake.

Crews responded to a tree on fire behind a home in the 200 block of South Shore Drive at 3:33 a.m., according to a statement from the Wauconda Fire District.

When crews arrived, they found heavy fire coming through the roof of a single-story home and encountered heavy smoke when they tried to search the home, fire officials said. It took about a half an hour to extinguish the flames.

Joanne Till was found inside and pronounced dead at the scene, according to the Lake County coroner’s office. Autopsy results are pending a toxicological report.

It wasn’t clear if there were functional smoke detectors inside the home, fire officials said. The Illinois State Fire Marshal is assisting with the investigation into the cause of the fire.