Firefighters arrived about 3 a.m. this morning in the 7800 block of South 228th Street, where they had been told a dumpster may be on fire.
Instead, they found a blaze in three outdoor canopies that are used to store soiled linens prior to cleaning in the commercial laundry facility at the address.
Three Fire engines and an aid car joined the initial emergency unit, and crews used a fire fighting foam to put out the blaze, which was deep inside the tightly packed linens.
A fire investigator ruled the cause to be spontaneous combustion in a bin of dirty shop towels, according to Kent Fire.
No damage to the building itself was reported.
No one was injured.