Flames shot out of the 4-story building at 118 West 2nd Street, as firefighters from surrounding areas arrived around 11:15 a.m.
The blaze ravaged the third and fourth floors as firefighters worked to contain it for more than an hour.
The roof collapsed around 12:30 p.m., forcing some firefighters to evacuate, initial reports say.
Firefighters had the blaze under control as of 2 p.m.
Have photos? Email clevine@dailyvoice.com
This is a developing story. Check back for more.
Click here to follow Daily Voice Northern Valley and receive free news updates.