A two-alarm fire caused serious damage to a Petaluma home early Sunday and sent one elderly resident to the hospital with breathing problems, said Petaluma fire officials.

Petaluma firefighters were called to a home on Willow Drive at 1:58 a.m. with reports of a house on fire.

When Battalion Chief Russ Rasmussen arrived he called for a second alarm, bringing additional help from throughout the south county due to the size of the fire and because some firefighters needed to help the man requiring medical aide.

The fire apparently started on the second floor and spread into upstairs bedrooms but was stopped before it spread to the rest of the home.

Rassmussen estimated the damage to the home and contents was about $100,000.

The cause remained under investigation.

Five people live at the home, including children ages 7 and 9. Two people were home when the fire started.

An elderly man suffering from smoke inhalation was taken to Petaluma Valley Hospital.

The Red Cross provided temporary housing for the five residents.

Petaluma firefighters were helped by Rancho Adobe, Cal Fire. The second alarm brought aid from San Antonio, Wilmar and Lakeville fire departments.

Schellville firefighters came to Petaluma from the Sonoma Valley to provide additional coverage should other calls occur.