SPRINGFIELD (AP) — Police and fire officials are investigating the cause of a Springfield house fire in which four people died overnight.

The (Springfield) State Journal-Register reports (http://bit.ly/UAUtNq ) firefighters were called to the scene at 11:43 p.m. Thursday. When they arrived four minutes later, the single-family home was fully engulfed in flames.

Firefighters used a ladder to help a woman thought to be in her late 50s escape from a second-story window in the back of a house. Springfield Fire Chief Ken Fustin says her condition and injuries weren't immediately known.