The causes of the remaining two fires are officially listed as "undetermined," but both are considered suspicious due to the absence of any clear ignition sources, per SFD.
No injuries have been reported.
What they're saying: Seattle police say detectives have not determined if the same person or people are responsible for all of the fires, but "we do know that there is an arsonist in our midst," spokesperson Detective Eric Munoz told FOX 13.
What's next: Officials are urging residents to check their security cameras and offering a $10,000 reward for tips.