Interstate 95 in Philadelphia could be closed for months after lanes partially collapsed on Sunday with commuters beginning to face heavy volumes of traffic Monday morning.

Northbound Interstate 95 lanes partially collapsed Sunday morning after a tanker truck caught fire underneath the highway, causing lanes above to buckle. Pennsylvania Gov. Josh Shapiro (D) said in a statement that preliminary reports suggest the truck was carrying a petroleum-based product.

The southbound side of Interstate 95 is “not structurally sound to carry any traffic,” the governor added. He noted that authorities have set up detours to “ensure folks can safely get to where they need to go.”

Shapiro also said that the “complete rebuild” of the highway could take months, adding that he would have an exact timeline once engineers and the Pennsylvania Department of Transportation finish their review of the collapse.

“I-95 is a critical roadway that supports our economy and plays an important role in folks’ everyday lives,” Shapiro said in a statement. “My Administration together with the [Philadelphia Mayor Jim] Kenney Administration and all of our partners are all hands on deck to repair this safely, safely, and as efficiently as possible.”

Officials warned that the detours will lead to significant delays in the coming weeks.