SAN FRANCISCO (Map, News) - A fire alarm on four legs may have been the only difference between an unfortunate two-alarm fire in the Bayview district and a deadly Easter tragedy.

Residents of the home, who declined to be named, spent their Easter Sunday pulling charred contents from the three-story wood-frame house in the

1200 block of Revere Avenue. They said the batteries were dead in the home’s smoke detectors, but that didn’t stop their pet Dalmatian, Lady, from sounding her own alarm.

Lady smelled the smoke early and entered a bedroom, waking the occupant with a whimper, family members said. Four adults and one child escaped before the flames engulfed the home, authorities said. Nobody was injured, and both Lady and her other canine friend made it out of the home safely.

The five residents were displaced after the blaze gutted their home, according to San Francisco Fire Department officials. The fire was first reported about 5:11 a.m., and it took 66 firefighters to get the blaze under control by 6:25 a.m.

While a keen sense of smell may be one reason canine companions make good smoke alarms, fire officials urge residents to maintain their mechanical detectors. In 2007 alone, San Francisco firefighters fought more than 1,400 fires at homes without working smoke detectors. With spring just beginning, fire officials said it’s a good time to incorporate a smoke detector battery check with spring cleaning activities.

Residents of the Bayview home said they believe the fire was caused by an electrical shortage. Despite being homeless, they were more than grateful for being unharmed, thanks to their spotted friend.

bbegin@examiner.com