A DEP spokesman says the 12-inch break in a city water main appears to have caused the collapse on a street Tuesday.
The crater opened in the middle of 23rd Street in Greenwood Heights, leaving the road impassable.
Workers had been excavating to determine whether a city main line was the source of the problem or a private service line. Road repairs are underway.
The street crumbled and swallowed a school bus, just moments after the last child was dropped off.
Greenwood Heights residents say they have water, heat, power. It's the noise from crews on 23rd St. repairing sinkhole that's the problem. pic.twitter.com/U2pKnFvSAB— CeFaan Kim (@CeFaanKim) December 7, 2016
Workers were ripping-up the street to locate the break.
As they did, water service remained shut down to hundreds of residents up and down the block.
Water service was restored by Wednesday afternoon.