A 46-year-old Adams Township man was killed Sunday evening when the motorcycle he was driving rear-ended another motorcycle in Penn Township, authorities said.

Joseph Schriver was pronounced dead at the scene. He was not wearing a helmet. Schriver was a public works employee for Adams Township.

The other motorcyclist, an Evans City man believed to be in his late-50s, was wearing a helmet and suffered minor injuries, Penn Township police said, but he refused medical treatment. Police did not immediately release his name.

The men were friends and they were riding together, headed to their homes, police said, when the crash occurred around 7:15 p.m. on Airport Road at Steppland Road in front of Penn Christian Academy.

Butler County Chief Deputy Coroner John Hanovick pronounced Schriver dead around 7:30 p.m. He died of blunt force trauma to the head, Hanovick said. No autopsy was performed, but standard toxicology tests will be conducted.

A police accident reconstruction investigation is also ongoing. Additionally, Penn Township officer Alyssa Mathews said police also plan to review surveillance video from Penn Christian Academy as part of their investigation.

Mathews, the investigating officer, said Schriver was traveling behind his friend on Airport Road when he struck the back of the other cycle, which was slowing to make a left turn onto Steppland Road.

Both men fell off their bikes. Two LifeFlight nurses on their way home were first to come upon the crash and stopped to help. LifeFlight is based at the nearby Pittsburgh-Butler Regional Airport.

The nurses administered cardiopulmonary resuscitation, but to no avail, authorities said. A Butler Ambulance Service crew also assisted.