BUFFALO, N.Y. (AP) — A city of Buffalo employee was killed and two others were wounded Thursday when the city pickup truck they were in was struck multiple times by gunfire from a passing vehicle, state police said.

The shooting in the southbound lanes of Interstate 190 just north of downtown Buffalo was reported at 11:20 a.m.

State police were searching for a dark-colored Jeep Grand Cherokee believed involved in the shooting and asked other motorists who might have been traveling on the busy highway at the time to come forward with dashcam video.

“We have several leads that we are working on, but currently we do not have a motive for the shooting,” state police Maj. Eugene Staniszewski said at a news conference. “This is believed to be an isolated incident and we have no information that there is a threat ongoing to the community at this time.”

The victims were employees of the Buffalo Sewer Authority and had just finished a job when they were shot as they drove back to the Sewer Authority building, Mayor Byron Brown said.

The driver of the pickup tried to evade the gunfire but was struck, along with the two passengers, Brown said. The driver survived.

“Who could have ever imagined that something like this would happen to three Sewer Authority employees as they are at work, doing the right thing, doing the people’s business?” Brown said after meeting with the victims’ relatives and co-workers. “This has to stop.”

One employee was in serious condition Thursday afternoon. The other had what were believed to be non-life threatening injuries, Staniszewski said.

Traffic cameras showed traffic in the southbound lanes stopped with an ambulance and several law enforcement vehicles in the roadway in the hours after the shooting. Traffic was diverted off the highway, which runs north and south through Buffalo and Niagara Falls from the mainline New York State Thruway, until about 3 p.m.

The names of the employees were not immediately released.