Mayor Louis Manzo said calls started coming in around 7:30 a.m. that Swamp Road, a small private road in a wooded area, was washed out.
Manzo explained that Swamp Road is carried over a ravine by an embankment that is some 40 to 50 feet high.
Chopper 6 video of large hole in Mullica Hill, New Jersey
In that embankment were pipes in a culvert that allowed water to flow through.
Over time, Manzo said, those pipes had become clogged, allowing water to build up on one side of the embankment.
Then, Friday morning, the water pressure became too great and it blew out the embankment, washing away part of Swamp Road.
An early estimate is that 50,000 gallons of water then flowed through the woods and into Raccoon Creek.
News conference on road collapse in Mullica Hill, N.J.
Manzo said there were no injuries and the current assessment is that there was no property damage. However, water service and power are currently out, and officials are working on restoration.
They will also determine whether those residents will need to be temporarily relocated.
Manzo said there are four other roadway structures that are being evaluated due to the torrent of water, including a small bridge that connects Swamp Road to Mill Road and two culverts that go under Raccoon Creek.