PORTLAND, Ore. (KOIN) — Drivers traveling across or near Portland’s Steel Bridge may have had their evening commute disrupted thanks to a fire on Wednesday.

Just before 5:30 p.m., Portland Fire and Rescue announced crews were responding to a blaze at the west end of the Steel Bridge near Northwest 1st Avenue and Northwest Everett Street.

The crews were clearing out by 6:45 p.m., according to a PFR tweet, but Portland Fire and Rescue spokesman Rick Graves said battling the blaze wasn’t easy: They needed to use a manhole to access the area, which was cluttered with unprotected needles and trash.

Authorities say one person suffered from smoke inhalation, but has been treated for non-life threatening injuries.

PFR tells KOIN 6 News the fire sparked behind a “decorative cinder-block wall” at what the Oregon Department of Transportation says was some type of camp underneath the bridge’s on-ramp. It’s not yet clear what started the fire.

As crews continue digging things out from under the ramp, fire officials and ODOT engineers are working to determine if it still is safe to use. In the meantime, all eastbound traffic on the bridge will be blocked until Thursday at least, according to ODOT.

“Extensive tunnels and areas you wouldn’t naturally think someone could be but we’re now doing a very thorough search to hopefully make sure that the entire area underneath the steel bridges enclosed by the cinder block area is clear,” Graves said.

Avoid the area if possible.

Stay with KOIN 6 News as this story develops.