A fire and explosion at a Spokane Valley dental office Monday sent glass and debris flying across a parking lot and apparently dislodged a large chunk of concrete from one side of the building.
Fire investigators pored over the rubble of the morning fire in an attempt to determine the cause of the blaze at 12509 E. Mission Ave., said Spokane Valley Assistant Fire Marshal Bill Clifford.
Officials reported that no one was hurt, despite a powerful blast that originated in a room containing oxygen and nitrous oxide tanks.
The fire began about 7 a.m. in the office of Drs. Kenji Higuchi and Daniel Skinner on the first floor of the Valley Mission Professional Building, and 911 initially received a report of light smoke seen in the building.
Within minutes, an AMR ambulance crew dropping off a patient at Valley Hospital and Medical Center, located directly across Mission from the office building, reported an explosion accompanying the fire.
“We had glass blowing out of the front and both sides” of the building, Clifford said.
One employee was inside the dental office when the fire started but said there was no smell of smoke prior to the sudden explosion, Clifford said. That employee got out without injury, he said.
If the fire had occurred 30 minutes later, there might have been a half-dozen employees inside, Clifford said, with the potential for serious injury.
By afternoon, investigators were attempting to pinpoint the cause. The room where the oxygen and nitrous oxide tanks were kept was a scene of “total destruction,” Clifford said.
Nitrous oxide in tanks, commonly used in dental practices for anesthesia, can explode when exposed to extreme heat.
Clifford said it is not clear whether the fire started prior to the explosion.
On the east side of the building, a large chunk of concrete fell to the ground.
The two-story building also houses a pharmacy, obstetrics and gynecology, and other medical professionals. All of those offices had to be vacated, and it was unclear Monday when they could reopen. Damage from the fire was largely confined to the oral surgery office. The rest of the building has substantial smoke damage, Clifford said.
Several patients arrived for appointments during the fire and had to be turned away, Clifford said.
Firefighters retrieved the computer system of the oral surgery office. An employee said efforts were under way to locate temporary office space quickly to continue treating patients. The office phone number has been transferred to another phone and is being answered.
The employee said patients will be contacted in the next few days about rescheduling appointments.
Clifford said a structural engineer will be needed to examine the soundness of the building, but he said it appeared the building could be cleaned and repaired.
Spokane Valley firefighters were assisted by units from Spokane County Fire Districts 8 and 9 and the Spokane Fire Department. More than 10 fire trucks were sent to the scene, and Mission was temporarily closed.
It took about an hour to bring the fire under control.