Leo Tam said he’s counting his blessing following a basement explosion that sent four people to the hospital, three of them with serious injuries.

“It was a loud explosion. And then it was a little bit of shaking,” Tam said.

Tam lives next door to the three impacted homes, and has not been able to go back inside his home.

“I’m just waiting for buildings personnel to tell me what the next steps are,” Tam said.

He said at night people often speed through his East Flatbush neighborhood. So, he initially assumed the boom he heard on Thursday night came from a crash.

Instead, fire officials said it came from a natural gas leak from inside a home.

“It could have been a lot worse. If someone was outside in the backyard, it could have been deadly,” Brett Asher, interagency coordinator with NYC Emergency Management, said.

Fire department sources said they are investigating a gas connection in the area near a stove in the basement.

Asher said the victims are lucky to be alive. The impacted households though may not be able to go back home.

“They’re [Department of Buildings] still doing an investigation. They’re not sure if it has to be demolished yet, but of the looks of it, probably,” Asher said.

The Department of Buildings has issued a full vacate order for the building where the explosion came from and the two adjoining homes.

Of the three households, 11 people are being helped by the Red Cross with temporary shelter and financial aid.