Portland firefighters douse the site of a gas explosion in Northeast Portland, Oct. 19, 2016.
Amelia Templeton / OPB
A firefighter climbs a ladder through dense smoke as he and others battle a blaze after a gas explosion in Portland, Ore., Wednesday, Oct. 19, 2016.
Don Ryan
Portland firefighters douse the site of a gas explosion in Northeast Portland, Oct. 19, 2016.
Amelia Templeton / OPB
Portland firefighters douse the site of a gas explosion in Northeast Portland, Oct. 19, 2016.
Amelia Templeton / OPB
No fatalities have been reported. People in the vicinity heard and felt the explosion at NW 23rd Avenue and Glisan Street.
Amelia Templeton / OPB
Streets in Northwest Portland were shut down near the site of a powerful gas explosion, Oct. 19, 2016.
Amelia Templeton / OPB
Smoke rises as firefighters battle a blaze after a gas explosion in Portland, Ore., Wednesday, Oct. 19, 2016.
Don Ryan
The gas explosion happened at NW 23rd Avenue and Glisan Street in Portland Wednesday morning.
Amelia Templeton / OPB
Portland firefighters at the site of a powerful gas explosion in Northeast Portland, Oct. 19, 2016.
Amelia Templeton / OPB
Streets in Northwest Portland were shut down near the site of a powerful gas explosion, Oct. 19, 2016.
Amelia Templeton / OPB
Damage from a gas explosion at NW 23rd Avenue and Glisan Street in Portland
Amelia Templeton / OPB
The gas explosion shattered windows in the vicinity.
Amelia Templeton / OPB
Several surrounding businesses sustained damage from the gas explosion that hit downtown Portland this morning.
Courtesy of Portland Fire and Rescue
Smoke billows up from a gas explosion fire in Northwest Portland.
Courtesy of Ray K Farmer
Courtesy of Portland Fire and Rescue
Debris from Wednesday morning's gas explosion in Portland blankets the street.
Courtesy of Portland Fire and Rescue
Amelia Templeton / OPB
Firefighters respond to a gas explosion in Northwest Portland.
Courtesy of Portland Fire and Rescue
Multiple firefighter injuries are reported at the scene of the fire.
Courtesy Portland Fire and Rescue
Smoke plumes from the site of a gas explosion that hit Northwest Portland Wednesday morning.
Courtesy of Zarek Valentin
Portland Fire & Rescue are at the scene of a natural gas leak at NW 23rd Avenue and Glisan Street. Multiple firefighter injuries are reported.
Courtesy of Matt Riley
Fire officials have ruled an Oct. 19 gas explosion in Northwest Portland was caused unintentionally.
The blast injured eight people, and destroyed one building on Northwest 23rd Avenue. It also damaged several other businesses in the area.
Portland Fire and Rescue’s Arson Squad said Monday that gas leaked into the basement of the building at 500 NW 23rd Ave. that exploded after an excavator struck a steel gas line.
"The contact pulled the pipe out of a fitting that was further underground, which started the release of natural gas," a press release from Portland fire officials said. "The natural gas then traveled under ground near the pipe and entered the basement."
The people injured in the explosion include three firefighters, two police officers and three civilians.
Because electricity was still on in the building at the time of the explosion, investigators said they weren’t able to determine exactly how the gas ignited.
"Due to the number of possible electrical and other ignition sources in the basement, fire investigators are classifying the specific ignition source as unknown at this time," the release stated.