A stretch of Interstate 80 in Morris County, New Jersey, that’s been plagued by sinkholes in recent months will be closed for at least “several weeks,” an official said, as crews investigate up to 90 “voids” lurking below the surface.

The New Jersey Department of Transportation says it will be several weeks before the sinkhole that opened up along Interstate 80 in Wharton will be fixed as work to repair that cavity continues.

The eastbound lanes of Route 80 are expected to remain closed for at least another three weeks to get to the root cause of two sinkholes that have opened up in the past two months.