The incident happened on Delaware Street in the Donegan Hills section late Wednesday, when several residents called 911 to report the strong smell of gas.
Firefighters evacuated about 20 homes, fearful of an explosion.
One homeowner thought the smell was coming from his basement, and when he opened the door, a mini-explosion took place.
"The guy went down into his basement and he smelled gas," a neighbor named Dennis said. "He opened a door, and it blew up in his face. He got burnt on the top of his head here, but I was talking to him and he seemed to be OK."
He and another person were rushed to Staten Island University Hospital North, one in serious condition. A firefighter also suffered minor injuries.
The Department of Buildings was also on scene to check the structural stability of the house, which suffered extensive damage from the explosion.
It was a very fearful situation for area residents, who shuffled out into the cold with very few of their possessions.
"The fire department went back into my house," one man said. "And they said, 'The readings now are at a higher level, and we're going to shut your power, shut your gas lines, and we need everybody out of the house.'"
Crews remained on the scene as they continued the investigation. The cause of the leak is still unclear.