A popular local athletic club is closed in Portland, Oregon, after a man drove a car full of explosives and propane into the building on Saturday.

Authorities responded to the Multnomah Athletic Club just before 3 a.m., after employees reported a vehicle had crashed into the building and caught fire. The driver was found dead inside, according to the Portland Police Bureau.

Portland Fire & Rescue arrived to control the blaze. The Portland Police Bureau's Explosive Disposal Unit was called in after evidence explosives was discovered on scene.

Investigators found multiple incendiary devices, improvised explosive devices and propane tanks, according to police. Some had partially detonated; others were in "varying states of activation," police said.

Officer Jim DeFrain, who leads the explosive disposal unit, said his team was still processing more than 14 hours after being called in. Robots were deployed as a remote precaution given the risk that remaining devices could still be triggered — though DeFrain acknowledged the technology has its limits.

"I've been a bomb technician here in the city for over 13 years," DeFrain said. "This is by far the most complex scene that I've ever dealt with."

FBI agents and Bureau of Alcohol, Tobacco, Firearms and Explosives personnel are assisting local police.

Portland Police Chief Bob Day described the incident as “isolated” and said he does not believe it constitutes an act of domestic terrorism. He deferred questions about the driver’s identity to the medical examiner’s office, which is still working to make a determination.

“They are the only ones who can make that notification and and so we are following their lead,” Day said. “They are on scene, but they have been unable to determine the identity of this individual because of the risk involved as we continue to clear away other explosive devices.”

The Multnomah Athletic Club — known locally as “The MAC” — is closed indefinitely. The eight-story clubhouse, within walking distance of downtown Portland, houses restaurants, swimming pools, exercise studios, a conditioning room, and ballroom and banquet facilities.

General manager Charles Leverton called the club a community, not just a building.

"So for the Mac members that are out there...You know, I think, pull together and do what we do best, which is stay together and support each other right now," Leverton said. "Support the law enforcement and getting them moving along, because nothing can happen until that finishes."