A Slippery Rock man was driving under the influence Friday, Sept. 5, when he struck and seriously injured a man who was working along a Mercer County road, according to police.

The man, who was working in a culvert off the west side of North Liberty Road in Liberty Township, Mercer County, was taken by medical helicopter to an Ohio hospital with multiple skull fractures and broken ribs and a compound fracture to his right leg following the crash, police said.

Police charged Tristen Lee Galarza, 27, Monday, Sept. 8, with one felony count each of aggravated assault by vehicle while DUI, accidents involving injury, DUI and misdemeanor operating without an ignition lock following the Friday incident.

Galarza’s preliminary hearing is scheduled for 9:30 a.m. Sept. 17 before District Judge Douglas Straub. He’s being held in Mercer County Jail on a $100,000 bail.

A witness on scene, who was operating an excavator at the end of the culvert, told police he saw a Toyota Corolla coming toward the area and attempted to yell for the man to move before he was struck.

The witness said he saw Galarza operating the vehicle and thought he had passed out behind the wheel, the affidavit said.

Police said Galarza reported seeing a red SUV drift into his lane, which caused him to go off the road and strike the man.

Police said Galarza showed signs of impairment during the interview. Police said Galarza reported taking a prescribed medication a few hours before the crash.

He was transported to AHN Grove City Hospital. The man who was struck was flown to Mercy Health – St. Elizabeth Youngstown Hospital in Ohio.

Police later discovered Galarza had a suspended license from three prior DUI convictions within the past 10 years and was required to use an interlock ignition system.