Two adults and two children died in a three-alarm fire in Prospect Heights Friday morning.

Residents who escaped, described thick black smoke engulfing the building. The residents say they used the fire escape at the back of the building. But some residents say they could not reach the fire escape and had to jump from windows. One witness says she saw a man help his family jump to safety.

Fire officials say the the cause of the fire is suspicious. They are investigating if the fire was related to another fire that broke out in a nearby building.