FOND DU LAC, Wis. (AP) — Three tenants have died in a fire at a group home for people with cognitive disabilities in eastern Wisconsin Thursday, officials said.

Two residents escaped the fire, which started about 6 a.m. at the Fond du Lac group home, while three other tenants were found dead on the second floor, fire officials said. The residents who escaped alerted firefighters that others were still inside, according to Fond du Lac Fire Chief Peter O’Leary.

“We don’t know yet what transpired that they couldn’t get out. We look at smoke alarms, make sure they were working. Did they have a plan (to escape)? Did they know what to do?” O’Leary said.

The home is for adults who can care for themselves, but have cognitive disabilities, officials said.

“These people live independently. That’s part of what they do and I applaud them. I applaud people… given these types of situations. They’re trying to do the best they can with the cards they’re dealt. And I think these people here live great lives and it’s just an unfortunate awful tragedy today that we woke up to,” O’Leary said.

The first victim was found not long after the fire broke out. Fire officials confirmed several hours later that two additional victims were found.

O’Leary said firefighters encountered a large amount of fire and smoke when they arrived on scene and went room-to-room using a ladder to the second floor on the outside of the house. The victims were not immediately identified and fire officials didn’t identify the owners of the house, who were on the scene.

A team of about 10 investigators will begin searching the cause of the fire, which was believed to have started on a porch.