According to the building's owner, a commercial dryer used for cleaning towels used on patients failed to turn off, resulting in its contents catching fire.
One of the 70-plus firefighters who responded to the scene was on the second floor when that portion of the structure collapsed. He fell through to the first floor, resulting in his injury.
The injured firefighter was treated at Providence Saint Joseph Medical Center.
The blaze took about 43 minutes to extinguish.