The Fayette County Sheriff's Office received a call at 3:35 a.m. about a home on fire near the small city of Arlington, about 125 miles northeast of Des Moines.
Several fire crews responded and found the house fully engulfed in flames.
The fire burned through the building, leaving just a charred pile of smoking metal and siding. Ron Humphrey with the State Fire Marshal said the property was damaged so badly it would be difficult to collect enough evidence to determine the cause of the fire.
Authorities spent several hours Friday looking for the fifth body, which was recovered by early afternoon.
Humphrey added that the house was owned by an elderly man who rented part of it out to others. He said authorities believe three adults and two children were killed, but it may take some time to positively identify the bodies. He said the information was based on who they believed was at the home.
The bodies will be sent to the state medical examiner's office to confirm their identities.
Several agents with the State Fire Marshal remain on the scene, with assistance from the Iowa Department Of Criminal Investigation.
Take ABC13 with you!
Download our free apps for iPhone, iPad, and Android devices