A big gas explosion leveled several homes in northwest Baltimore on Monday, killing one woman and leaving six others injured, according to the Baltimore City Fire Department.

Governor Larry Hogan said, “We are closely monitoring the situation in northwest Baltimore following this morning’s horrific explosion.”

“We have reached out to offer our full support to the ongoing response and recovery efforts and are deeply grateful to the first responders on the scene,” he added.

"We're prepared to be here throughout the night, as long as it takes," city fire spokeswoman Blair Adams told reporters late Monday afternoon.

"We're working diligently on trying to make sure that we comb through every area to determine if there are any (more) victims inside (under rubble)."

The cause of the gas line blast was not immediately known. The blast happened a short walk away from Reisterstown Road Plaza, a major retail hub in the region.