This weekend, a large fire damaged the 10 Freeway in Los Angeles, shutting down a primary transportation route for hundreds of thousands of people.

State Fire Marshal Daniel Berlant said investigators “have been able to confidently determine” that the blaze was caused by arson, though the person or persons involved have not been identified.

The investigation is ongoing into “what we believe to be malicious and willful intent of starting a fire,” Berlant said.

But how did those flammable materials end up under the freeway? It’s part of a government program that leases that space to private citizens and companies.

Caltrans’ Airspace and Telecommunications Licensing Program — often called simply Airspace — “is responsible for leasing and managing those properties or sites held for a transportation purpose that can safely accommodate a secondary use,” the agency said on its website.

“More simply put, Airspace leases specific areas within state highway right of way,” Caltrans added.

Federal authorization is also required before a lessee can be approved, according to Gov. Gavin Newsom.

In this case, the space was being leased to a company called Apex Development Inc., though the lease has expired and that entity is involved in litigation with the state. Newsom expects the case to be heard in court in early 2024.

“This guy and this organization, whoever the members of that particular organization are, have been bad actors,” Newsom said. “We’ve been in a litigious posture for some time. They stopped paying their rent, they’re out of compliance, and as was stated yesterday … they have been subleasing this site to at least five, maybe as many as six tenants, without authorization from Caltrans or authorization from our federal partners.”

While that investigation is ongoing, appraisals into what will be needed to reopen the roadway showed some positive signs, Newsom said Monday afternoon.

“The structural integrity of the deck appears to be much stronger than originally assessed,” Newsom said. “That does not mean that we are moving forward without consideration of a demo[lition]. Quite the contrary. We are assessing additional samples, but the preliminary samples show more positive results than initially anticipated.”

A potential window for reopening has not yet been determined.