The family of a Penn State graduate assistant killed in a car accident in June is suing the driver police say pushed her car into oncoming traffic.

Sarah Donaldson was traveling westbound on Route 322 in Potter Township in Centre County on June 16 when her Toyota Prius was struck from behind by a tractor-trailer, according to the lawsuit.

Her car was propelled into oncoming traffic where it collided with another large truck, according to the lawsuit. Donaldson, 28, was pronounced dead at the scene.

Kevin Donaldson, Sarah's brother, is suing the driver of the tractor-trailer, George E. Donley, and his employer, Davidson Brothers, Inc. for negligence, wrongful death and survivorship. Michael Davidson, the owner of the Bellefonte trucking company, 450 Runville Road, is also listed as a defendant in the suit.

Kevin Donaldson is seeking an amount "far in excess of one hundred thousand" dollars from the defendants, according to the lawsuit.

According to the lawsuit, Sarah Donaldson graduated from Penn State's Schreyer Honors College in 1998 in the top 10 members of her class. She eventually received a master's degree in pathobiology in 2005 from Penn State. At the time of her death, Donaldson was working as a research assistant at the university, according to the lawsuit.

At the time of her death, Donaldson was returning to her State College residence after a weekend trip with her fiancé in Harrisburg, according to the lawsuit. Donaldson was to be married this past Saturday, according to the suit.

The suit says Donley did not adhere to a PennDOT warning of slow moving vehicles in the area and did not keep a safe distance between Donaldson and himself.

"Defendant George E. Donley was operating his tractor-trailer combination in an inattentive, reckless and careless manner, at an inappropriate speed, in reckless proximity to the rear of decedent Sarah C. Donaldson," the lawsuit states.

Donley and Davidson could not be immediately reached for comment.