A Ford City High School cheerleader was killed and her brother and cousin seriously injured yesterday morning in a collision with a tractor-trailer truck that caused a 20-ton load of steel to fall on the teen's car.

The accident shook the Armstrong School District, literally and figuratively, occurring outside the district's administrative offices at Route 66 and Pleasant View Drive in Manor Township.

"I thought someone had fallen or dropped something heavy upstairs," one office worker said, adding that the collision's impact shook the building.

From left: Shawna Petrosky, Eric Petrosky Jr. and Greg Heater.

William H. Kerr, superintendent of schools, identified the victims as Shawna Lynn Petrosky, 17, her brother, Eric "Bubba" Petrosky Jr., and their cousin, Greg Heeter. The boys are eighth-graders at Ford City Junior-Senior High School. Shawna was in the 11th grade.

Shawna had recently completed her driver's education course requirements, said school district spokesman Jonathan Szish.

"It's an unspeakable tragedy," Mr. Szish said. "Our thoughts and prayers go out to the families. We're all hurting because we lost a student."

The accident occurred shortly after Shawna and her brother, both of Manor, had just picked up their cousin. They were driving on Pleasant View and were on their way to school, about a mile away.

As Shawna attempted to cross Route 66 at 7:19 a.m., her car entered the path of the tractor-trailer driven by Sam Livengood. State police reported that the car failed to stop at a flashing red light before entering the intersection.

About 50 feet of skid marks left by the truck ended where it impacted the car on the driver's side, causing the smaller vehicle to roll onto its roof.

Eric Petrosky was lying outside the vehicle when Dr. Kerr ran outside to aid them.

The collision also caused the coiled steel, weighing 41,200 pounds, to break from its mooring. The load crashed into the back of the truck cab, and then rolled or hurdled over it, landing on the upsidedown car.

Armstrong County Coroner Robert Bower said Shawna likely was killed instantly by crushing injuries.

The boys were taken to Children's Hospital where Eric was admitted in fair condition and Greg was in serious condition, a hospital spokesman said.

Mr. Livengood, 44, of Saltsburg, was taken to UPMC Presbyterian. He was conscious when he was taken from the scene.

The steel load was being hauled from Allegheny Technologies' Ludlum plant in Leechburg to an undisclosed destination.

State police Lt. Thomas Dubovi said investigators and truck inspectors will evaluate information gathered at the scene. Among their concerns are whether the steel load was within legal weight limits and whether the steel was properly tethered to the trailer.

State law and the rules and regulations of the Federal Motor Carrier Safety Administration require the loads to be properly secured "to prevent movement in all directions, side to side and front to back," state police spokesman Jack Lewis said.

The gross weight of the tractor-trailer combination and its load legally cannot exceed 80,000 pounds in Pennsylvania without a special hauling permit, Trooper Lewis said.

Lt. Dubovi said investigators also will work to determine the cause of the accident. Traffic signals at the intersection normally work on a regular cycle at that time of morning. During off-peak hours, however, Route 66 traffic has a flashing yellow light and the Pleasant View traffic has a flashing red light.

State police said the light was flashing at the time of the accident but it was not clear why. District 10 PennDOT spokesman Mark Hillwig said the light is maintained jointly by Manor Township and Ford City.

The speed limit along Route 66 at that intersection is 40 mph.

A spokeswoman for Cable Trucking/Clay Transport Inc., the Saltsburg company for which Mr. Livengood had been driving, declined comment yesterday.

By coincidence yesterday, the Armstrong School District was about to conduct a training session at its headquarters for all of the district's counselors, Dr. Kerr said.

They had begun arriving at the administration building around the time of the accident, and they immediately were dispatched to the junior-senior high school.

"We have immediate concern for the Petrosky and Heeter families, and, of course, we're also a school family," Dr. Kerr said.

The children's relatives, who live near the administration building, were provided shelter and counseling, essentially at the scene of the crash.

Some parents went to the school to take their children home early yesterday.

"We're trying our best to deal with the facts [instead of rumor]," Dr. Kerr said. "When a tragic accident happens, it puts in perspective what life is all about."

He and Mr. Szish said all three of the children are well-known and liked at Ford City High.

The Petrosky children's mother, Rhonda, and their grandmother, Wanda Smock, operate Miller's Hoagies locations in Ford City and Kittanning.

Denise Czekanski, who works at the Ford City hoagie shop, said Shawna and her younger brother grew up around the business. Shawna worked there one or two days a week, she said.

"She was a beautiful girl," Mrs. Czekanski said. "And she was a good little worker."

The children's father, Eric Petrosky Sr., is a Pennsylvania state trooper stationed at the Everett barracks on the Pennsylvania Turnpike. He learned of the accident as he was beginning his shift yesterday morning, and he was relieved of duty, Lt. Dubovi said.

Route 66 in Manor was closed for more than five hours after the accident.