Now, they're sending out a warning to all restaurants, hair salons, and even bowling alleys where towels are used to clean things and then washed and tossed in the dryer.
Olympia fire investigator Brian Schenk gave KOMO News a close look at the dryer where the Oyster House fire started.
"I see a very distinct burn pattern here that shows me the fire came from the inside out," Schenk said. "It just looks like it's towels."
The restaurant manager said the night of the fire that they used the dryer just before closing.
It was the second restaurant fire in Olympia in two years caused by towels in the dryer, and the fifth in five years to other businesses including hair salons.
The cleaning towels that were left inside the dryer smolder for hours and then spontaneously combust. The greases and oils used in the cleaning process apparently don't all get washed out.
"And so when they get thrown in the dryer and left, they'll continue to spontaneously heat even after the dryer cycle has stopped and people have all left," said Assistant Chief Robert Bradley, the Olympia fire marshal.
The message from fire investigators is: Don't let the towels sit.
"When it is done, take them out, spread them out, let them cool down," Schenk said.
The fire scene is being preserved for the manufacturer of the dryer to bring its own investigator while the burned towels are sent off to a lab for testing. At the same time, renovation crews are getting the place cleared out so the rebuilding process can begin -- with some of the historic items left intact.
"And of all the things crashing, this counter top with all of the shells and historic things that are laid in here didn't get broken," said Kevin Godfey. "So we're going to save and restore that."
The restaurant might be ready top open by spring and the owners are wanting to look just like it did before the fire.