Two bodies were discovered inside a burning underground utility vault beneath a Fresno overpass Monday morning after firefighters navigated a hazardous confined space packed with live electrics.

The deadly blaze sparked a massive technical rescue response after smoke was seen rising from the bunker, which investigators say had been converted into a makeshift homeless encampment that may have existed for months.

“It was a challenging situation,” Fresno Fire Chief Billy Alcorn told KGPE. “Not only did you have a fire, but you also had live electrical down there in a confined space.”

Construction workers nearby reported seeing three people leaving the area where the smoke began before emergency crews arrived.

Authorities said people appeared to have dug a tunnel through dirt near the overpass to access the vault, which Alcorn said was never meant to be entered from the side.

Once firefighters safely entered the underground space, they found two bodies inside.

Crews then worked to fully extinguish the fire while making sure no one else remained trapped below.

The operation forced officials to shut off power to part of downtown Fresno so crews could safely work around the dangerous electrical infrastructure, leaving nearby buildings, including Matsen Towers, without electricity.

“Well, they’re not happy because it’s going to get hot,” resident Toni Lujan told the outlet. “It’s already getting hotter.”

Lujan, who lives across the street, said homelessness in the downtown area has become an increasing concern.

“I feel bad for them, but if they were doing something they shouldn’t be doing, they were taking risks,” she said.

Officials have not released the identities of the victims, and the cause of the fire remains under investigation.