FLINT, Mich. -- Five teens have entered not guilty pleas for allegedly killing a man by throwing rocks from a Michigan overpass along I-75.

All of the teens, ages 15-17, are being held without bond.

Each has been charged as an adult and could face life behind bars if convicted.

The teens were arraigned Tuesday.

"It's not a prank,” Genesee County Sheriff Robert Pickell said. “It’s second degree murder I don't think anybody's laughing.”

Last week, 32-year-old Ken White, father of a 5-year-old boy, was in a car going home after working on a construction job. Investigators say a group of teens throwing rocks at cars from an overpass near flint hurled one that crashed through the windshield and killed White.

"It took a good man and a good father away from us too soon,” said Amiee Cagle, the victim’s fiancée. “For some senseless act for it to be just a rock."

Police say the teens tossed at least 20 rocks from the overpass and hit at least eight vehicles.

While White was dying, police say the teens grabbed a bite to eat at McDonald’s.

The prosecutor doesn’t believe the teens intended to kill anyone, but he insists a crime was committed.

"The throwing of the rock or several rocks over the over pass created the likely result of great bodily harm,” said Genesee County Prosecutor David Leyton.

Attorneys representing two of the teens say they expect some of the charges to be reduced once prosecutors determine exactly who did what.