HAYWARD -- A fire official is crediting a quick-thinking 9-year-old boy for saving a disabled relative's life Monday afternoon.

Hayward Fire Capt. Thor Poulsen said the man, who uses a wheelchair, was alone in a bedroom with the door closed eating and smoking a cigarette when a fire broke out about 4:30 p.m. Monday.

His wife was in another room and heard the smoke detector sound, Poulsen said.

"The working smoke detector is really what caused anyone to check in on him," Poulsen said. "With the amount of fire and smoke damage, he could have easily passed away in that room before she even knew there was a fire in there."

Poulsen said the boy, who was visiting the home, ran and asked two neighbors for help. The men pulled the disabled man into another room and to safety.

Firefighters were called to the small house in the 27000 block of Tyrrell Avenue, and opened the roof to help control the one-alarm fire, Poulsen said. The cause of the fire was likely a dropped cigarette. The man burned his hands when he tried to put out the fire, and was taken to a hospital for treatment, Poulsen said. No one else was injured.

Damage to the contents and structure was estimated at about $12,000 to $17,000.

Reach Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.