It's one of the few bright spots to come out of Thursday's disaster in Lawrence, Massachusetts.
As his neighbors were evacuating, off-duty Lawrence firefighter Lt. Dave Amero ran house to house, shutting off the gas.
Amero said he realized there was a problem when his wife told him their house reeked of gas.
"I just started running around, shutting off meters. It was all I could do at the time," said Amero.
Moments later, Amero said he heard the explosion that leveled a house on Chickering Road. He soon found out the problem was so much bigger than he thought.
"Once I called the fire in ... they said they had 10 fires going on at once. I had no idea what was going on," said Amero.
Armed with only that wrench and a roll of tape to mark the houses he turned off, Amero worked door to door for 90 minutes. He estimates he was able to get to 50 or 60 homes.
"I've never experienced anything like it," said Amero.
Patrick Sweeney is one of many firefighters who gave Amero a well-deserved pat on the back.
"You look up to a guy like that. What Dave did was above the call of duty. He just acted right away," said Sweeney.
Amero and his family are among the thousands of people in south Lawrence unable to return to their homes. He said when he's not working, his family is staying with relatives in Salem, New Hampshire.