Israel Melendez was cleaning his truck outside his home on St. Paul's West Side about 2 p.m. Saturday when he heard the explosion.

He looked up and saw flames and debris falling around a house on the corner of Hall Avenue and W. Baker Street.

He knew the person who lived inside, Michael L. Schultz. Schultz, 74, lived by himself. He had had heart surgery and a stroke, neighbors said.

Melendez, 48, ran to the large stucco house accompanied by another neighbor, Paul Warner, 53.

They tried to get the door open, but couldn't. So Melendez broke through the window on the first floor. He stepped inside and saw Schultz lying on the living room floor.

He grabbed Schultz's shirt and pulled. With Warner's help, he got Schultz out through the window.

"There were flames everywhere, bro," Melendez said.

Warner told friends and relatives that he could feel the heat of the fire on the back of his neck as he pulled the victim away from the house.

When St. Paul firefighters arrived, they found the house "heavily on fire," said Assistant Fire Chief Matthew Simpson. It took 60 firefighters about 20 minutes to knock down the flames, which burned through much of the roof.

The cause of the explosion has not been determined, Simpson said. Neighbors speculated that it might have been caused by a gas leak due to the recent installation of some appliances. Xcel Energy workers remained on the scene inspecting other homes on the block. No other structures were damaged.

Schultz was taken to Regions Hospital in St. Paul, where he was in fair condition Saturday evening.

Warner's mother, Harriet Barriault, speculated that Schultz didn't immediately flee because he was looking for his cat, Tootsie.

Neighbor Steve Cardenas said Schultz, whom neighbors called "Sarge," was retired and lived quietly with his cat, occasionally going to the corner bar for a beer at happy hour.

Simpson said Melendez and Warner "absolutely" risked their lives to save Schultz, adding, "This is a sincere definition of courage."

"It's a good thing my son was here, or Mike might not be here today," Barriault said.