A massive fire believed to have started in a homeless encampment beneath the 110 Freeway has turned into a commuter nightmare in Los Angeles, with northbound lanes expected to remain shut indefinitely over fears the blaze may have damaged the roadway’s structure.

The fire erupted Monday night beneath an overpass in Wilmington, near the Port of Los Angeles, forcing authorities to shut down the busy roadway in both directions, according to the Los Angeles Fire Department.

The southbound lanes finally reopened on Tuesday morning, while the northbound lanes from Harry Bridges Boulevard to Channel Street are expected to remain closed indefinitely.

A California Department of Transportation spokesperson said that crews were still trying to assess the damage to the structure on the northbound side.

“We’re trying to get a sense of how thick that structural depth is on the freeway so we can see whether the fire has burned the underside of the freeway, which could impact the concrete, the rebar, the girders,” a Caltrans spokesperson told KTLA.

“But until we can get in there, until it gets cool enough, until the Los Angeles Fire Department can get that fire knocked down, we can’t get a sense if it has even damaged the freeway and if a load of traffic can be on there.”

LAFD Public Service Officer Lyndsey Lantz told The Post that the structural integrity of the freeway is something they are keeping an eye on.

“It is something we are watching, but no confirmed structural compromise at this point.”

The blaze was initially reported as a “rubbish fire,” according to fire officials. Investigators believe it was sparked by homeless people, FOX 11 reported.

“There are encampment materials inside and around that access portal. There’s a tent and tons of debris,” Lantz previously told The Post about the area.

The department later posted a picture on Instagram of all the burned debris that fire crews were working to clear from the encampment in order for them to tackle the blaze.

“While firefighters have removed a large amount of debris from the space, burning construction timber and other unmovable materials will require sustained suppression,” the LAFD said.

Los Angeles City Councilman Tim McOsker on Tuesday introduced a motion raising serious concerns about public safety and the damage the fire has done, calling for stronger safety measures and oversight between the agencies.

“What we saw today was a clear breakdown in communication from the state to the city,” McOsker said in a statement. “The California Department of Transportation needs to be a true partner with the city, not just in responding after the fact, but in being proactive, securing these spaces, and working with our emergency notification systems.”

“The delays we saw today are unacceptable, and we need to make sure it does not happen again.”

Osker’s motion calls for the possible installation of “fire detection, warning and emergency notification systems within freeway infrastructure,” according to the release.

Drivers traveling northbound near the Port of LA should expect delays as the closure remains in effect, with traffic diverted to Channel Street, according to California Highway Patrol.

No injuries have been reported and the fire is under investigation.

The Post reached out to Caltrans and LAFD for further comment.