SAN FRANCISCO (KGO) -- ABC7 News has learned the cause of two destructive fires in San Francisco were both accidental.
A fire in January killed one person at a Mission Street apartment building, displacing 40 others.
Investigators say the fire began in a wall but don't know what ignited the flames.
And a second fire that burned two homes in Potrero Hill last Christmas was electrical. It caused six million dollars in damage.