What caused latest New Jersey sinkhole on Route 287?

• The latest NJ sinkhole closed two left northbound lanes north of Exit 41.
• The sinkhole appeared during a Friday night rush hour.
• Sinkholes on Route 80, caused by mine collapses, are not related to the Route 287 void.

The latest sinkhole on a Morris County interstate, based on preliminary inspections, looks to be caused by an abandoned pipe ― and is not connected to the mine collapses that have crippled Route 80 for the better part of the last month.

The sinkhole developed during rush hour on Route 287 north in Parsippany-Troy Hills on March 21, forcing the closure of the middle and left northbound lanes just past Exit 41B.

The sinkhole is located in the left shoulder of northbound lanes of I-287 between routes 46 and 80, according to a map on the state Transportation Department's 511nj.org and photo of the scene.

"The two left lanes on I-287 northbound are closed after Exit 41B in Parsippany-Troy Hills due to a sinkhole in the shoulder. NJDOT is investigating the situation," said a spokesperson for the state Transportation Department in an email shortly after the void was discovered.

Plans in the area showed an abandoned pipe in front of the inlet, state Senator Joseph Pennacchio said.

Gov. Phil Murphy said it was a water pipe that collapsed and he expected the road to be repaired by Monday, March 24.

A video found a long section of collapsed pipe, about 80-feet long and 15-feet deep. Workers must dig a trench to remove the pipe and repair the roadway. Crews will also be checking a nearby box culvert for any damage.

The job is estimated to take three days, Pennacchio said.

That's a blink of the eye compared to how long repairs are expected to take on Route 80 in Wharton, where crews are already dealing with fixing two active sinkholes ― and that follows the repair of another sinkhole in December 2024 in the same location.

The Route 80 sinkholes are located on both the westbound and eastbound sides of the highway were created by abandoned mines ― many of which dot the landscape in Wharton, Dover and the aptly-named Mine Hill.