(THE HILL) – 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.

“If you are traveling along the I-95 corridor in the coming days and weeks, please pay close attention to local traffic alerts as we expect significant regional traffic impact,” Transportation Secretary Pete Buttigieg tweeted

Pennsylvania’s Department of Transportation has posted detour routes to a website it launched after the collapse. Pennsylvania Transportation Department spokesman Brad Rudolph told The Associated Press that motorists were sent on a 43-mile detour Sunday.

“Other streets closed for the response,” the agency added. “Avoid area. Plan and seek alternative travel routes.”

Southeastern Pennsylvania Transportation Authority (SEPTA) said it was adding three more trains to its Trenton, New Jersey line on Monday, and will add capacity on regularly scheduled trains to accommodate increased ridership.