A man died after driving a car loaded with explosives and propane into the Multnomah Athletic Club in Portland, Oregon, early Saturday morning, triggering a fire and major emergency response.

Police found multiple incendiary and explosive devices at the scene, some of which had partially detonated or were still active.

Bomb technicians, robots, and federal agencies including the FBI and ATF were called in due to the extreme danger, and officials described the scene as highly complex.

Authorities say the incident appears to be “isolated” and are not currently treating it as domestic terrorism, while the driver’s identity is still being confirmed, NBC News has reported.

The athletic club remains closed indefinitely as investigators continue clearing and securing the site.