Investigators are trying to determine the cause of a fire that left a Waterloo couple homeless late Sunday night (April 2, 2017).

Firefighters were called to 514 Johnson St. at 11:30 p.m. According to Captain Carl Reninger of Waterloo Fire Rescue, heavy flames were rolling out of the front door and windows of the structure when crews arrived.

Reninger said the couple who lived in the house escaped the fire and were outside when firefighters got to the scene. He confirmed that one person was transported to the hospital as a precaution.

According to Reninger, the blaze caused extensive damage to the living room, while the rest of the house had extensive heat and smoke damage. He said the fire started in the home's front entryway, but investigators don't yet know how it started.