Officials say cut gas pipe was found in the basement of an apartment building in Maryland. It was destroyed by an explosion.

Officials believe that a maintenance worker was performing plumbing work at Friendly Garden Apartments before Thursday's explosion.

Officials say cut gas pipe was found in the basement of an apartment building in Maryland. It was destroyed by an explosion.

Investigators discovered a cut gas pipe inside the basement of an Silver Spring, Maryland apartment building that was destroyed in an explosion and fire.

According to Scott Goldstein, Montgomery County Fire Chief Scott Goldstein, officials believe that a maintenance worker was performing plumbing work at Friendly Garden Apartments before the explosion.

"It's possible that the worker cut that pipe," Goldstein stated, NBC Washington reported.

The blast injured 14 people, including the maintenance worker. A fire official stated that three of the victims are in critical condition while 11 others sustained minor to moderate injuries. According to the official, the worker was speaking with investigators.

Although all residents of Friendly Garden Apartments have been found safe, investigators continue to investigate whether there were visitors or any other persons present at the building at that time.

T.J. Hall, a resident, told NBC Washington he smelled gas as he was about to leave on Thursday morning.

Hall stated, "When I left this morning I told my grandma that it smelled like gas."

Andre Kinard, a local resident, claimed he felt the blast.

He said, "I looked around and that was when I saw everything to my smithereens."

Multiple buildings were evacuated from the apartment complex on Lyttonsville Road. Three of the six buildings were deemed unsafe.

A fire official stated Friday that residents would be permitted to return to the three remaining buildings.