Bus stop in Amherst where an accident occurred Sunday.

AMHERST – A Northampton man is dead and the driver of the truck that struck him Sunday night in downtown Amherst is still being sought, according to the Northwestern district attorney’s office.

William E. Wanczyk, 55, was transported by Amherst Fire Department ambulance to Cooley Dickinson Hospital in Northampton after a truck slammed into a bus shelter at 141 North Pleasant St. in front of the post office, Mary Carey, a spokeswoman for the district attorney’s office, said in a statement issued Tuesday morning.

Wanczyk was pronounced dead shortly after 10 p.m. Sunday.

William Wanczyk’s daughter, Marlee Wanczyk, said when contacted by telephone that Tuesday was her 31st birthday.

“It’s traumatic right now. I’m having a hard time,” she said, and declined further comment about her father’s death.

Police said a green truck was seen traveling downtown with no headlights on at a high rate of speed around 9:30 p.m. when it began to fishtail and hit the bus stop, Carey said.

The state Office of Chief Medical Examiner will determine the cause of death.

The vehicle was abandoned north of the crash site. The driver has not been found.

Anyone with information about the accident is asked to call the Amherst Police Department (413) 259-3000 or the Massachusetts State Police Detectives Unit at (413) 586-9225.

The incident remains under investigation by Amherst Police, Massachusetts State Police assigned to the Northwestern district attorney’s office, MSP Crime Scene Services and MSP Collision Analysis and Reconstruction Section.