The Glenview Apartments, located in the 16000 block of Military Road, was undergoing a roof replacement when a heavy storm swept through, said Don Barberie of the SeaTac Fire Department.
Barberie said the roof was covered with a plastic sheeting, but the heavy rains managed to get under the sheeting. Rainwater poured into the attic as well as the second and third floors of the building.
"In the kitchen, on top of the appliances, on the carpet, by that time it was down to the very first floor," resident Luis Santana says.
Emergency crews responded to the flooding call and found significant damage to 13 apartment units. All 13 were declared unsafe and families had to move out.
The displaced families are being assisted with housing by the apartment management and American Red Cross.
There were no reports of injuries to any of the residents, and no word when crews might start fixing the mess left behind by Thursday's storms.