The small town of Pulaski was in shock and mourning Saturday and the police chief fought back tears after five schoolgirls were killed on their way to a birthday party by a speeding car that jumped a curb.

"This is the most tragic incident I've had to deal with in my 15 years (in police work)," Chief Reed Woodward said at a news conference.The girls - ages 12 and 13 - were hit by the 1975 Cadillac driven by a 17-year-old boy at 6:49 p.m. Friday as they walked to an overnight birthday party, Woodward said.

Woodward said it was particularly troubling for the community of 2,000 because many of the emergency personnel on the scene knew or were related to the victims.

"The heart of this police department and the community goes out to the families of the five fine young children who were killed," he said. At times the chief fought back tears as he spoke.

Woodward said a blood test on the 17-year-old driver, Scott Karcz, indicated there was no alcohol in his system.

Woodward said Karcz is diabetic and investigators were trying to determine if he suffered a seizure or if there was some other "medical reason" for loosing control of the car.

Karcz received his driver's license last February. He and his sister Tina, 11, a passenger in the car, were in critical condition in Green Bay hospitals late Saturday.

Karcz is a distant relative of one of the girls killed, Laura Karcz, 13.

The other victims were identified as Brenda Hylok, 13, Jessica McKeefry, 13, Jodi Prokop, 13 and Nicole Watia, 12.