The two fires at the Iowa Advanced Technology Laboratories last week were caused by the heat of the sun reflecting on the outside of the building, according to the University of Iowa Office of Campus Safety.

A statement from the office read that the heat from the sun onto the stainless-steel exterior of the building caused “underlayment materials to smolder,” but drywall kept the fire from entering the building.

The statement adds that the building has been covered with non-reflective materials, and the UI will conduct visual inspections until a permanent solution is found.

The lab was designed by renowned architect Frank Gehry, and is being renovated for an estimated $4 million to address the weather barrier that sits behind the wall’s metal panels that decorate the building. 

The fires occurred on Aug. 31 and Sept. 1 last week. A Hawk Alert went out around 1:29 p.m. on Thursday to alert the UI community to avoid the area, although a crowd of bystanders gathered on the Iowa Memorial Union’s patio.

Fire officials tore panels off the building to access the inner wall.

On the morning of Sept. 1, a second fire occurred at the lab, believed to be in the same spot as Thursday. The fire occurred around 10:29 a.m. and was put out within an hour.

Bruce McAvoy, the UI’s fire safety coordinator who was at the scene Friday, said the fire may have been caused by the reflection of the sun on the exterior of the building.