City of Janesville Department of Public works officials and crews discuss a sinkhole that opened up on North Washington Street in Janesville on Friday afternoon.
© Anthony WahlCity of Janesville Department of Public works officials and crews discuss a sinkhole that opened up on North Washington Street in Janesville on Friday afternoon.
City crews worked Friday afternoon to fill a massive sinkhole that broke open on a street on the city's west side after heavy rains earlier this week had washed out the ground beneath the roadway.

Crews at the scene Friday afternoon said it took three truckloads of gravel to temporarily fill a sinkhole the length and width of a large car that broke open at about 3 p.m. Friday, leaving a 15-foot deep chasm on the east side of North Washington Street just north of Highland Avenue and the Mercy Hospital and Trauma Center campus.

Troy Egger, a city of Janesville public works department crew leader, told The Gazette that one of his crew members has worked for the city for 31 years.

He said that worker said he has never seen a sinkhole the size of the one that broke open Friday.

Egger said the sinkhole formed above an 84-inch drainpipe that runs about 22 feet below the street and empties into the Rock River. Heavy rains that soaked the ground Wednesday night were responsible for the sinkhole, Egger said.
SINLHOLE

He said crews think the massive volume of stormwater running off during the rainfall overwhelmed the big pipe and began to scour out the ground above the pipe, washing away ground beneath the road.

"All that water and the ground around it had to go somewhere. It ended up in the river," Egger said.

Drivers initially reported there was a "dip" in the road, Egger said. It wasn't clear then to city crews that the depression actually had a sinkhole beneath it. It broke open as crews were en route, Egger indicated.

"I had come out to put out a 'Bump' sign to mark it. When we got here, the sheriff's office already had the street blocked off, and there was a huge hole," Egger said.

Nobody traveling on the street Friday drove into the sinkhole after it broke open, Egger said, but he said it could easily have swallowed a large car.

One Janesville resident said she witnessed the sinkhole opening up while she was driving past, and she came close to falling into the pit.

April McGinnis said she was heading north on North Washington Street when she noticed the street ahead had a dip with cracks forming. She said she almost couldn't get over in time as she passed the dip.

As she drove past, she looked back, and the depression in the street had given way to a gaping cavern.

"It looked like an oil on the road, a dark spot, but it wasn't. The darkness was ... there was no road there anymore," McGinnis said. "I pulled over and watched it continue crumbling open. Another truck behind me saw it, luckily. I was afraid because I didn't want somebody to fall in it."

McGinnis said another driver called police to report the sinkhole, which Egger said was 15 feet deep.

By about 5:30 p.m. Friday, crews had pulled out pieces of the crumbled roadway and filled the crater beneath with crushed gravel so people could safely drive on the street.

Crews on scene said a contractor would likely fill the sinkhole permanently and fix the road surface sometime in the coming week.