Firefighters said the fire was pretty minor, but the flames got into the walls, so they had to tear down the walls in all four apartments.
When they went upstairs, they found a bathtub with the water still running and flooding out the place.
They're not sure why the residents left the water running, but it did more damage to the apartment than the fire did.
Fresno firefighters also said they saved several apartment homes when they got a fire under control in a hurry late last night.
It broke out around midnight at valentine and San Jose in northwest Fresno.
Firefighters knocked down the flames quickly, contained most of the damage to the first floor, and protected the neighboring apartments.
Investigators say the fire started in a dryer downstairs, but nobody noticed it at first because they were all upstairs.
When they finally noticed it, one resident tried to douse the flames with a fire extinguisher, but she cut her hand on the glass and couldn't stop the fire.