“Jackass” star Ryan Dunn was reportedly hurtling in his Porsche down a rural Pennsylvania four-lane undivided highway at 130 miles per hour, when it flew off the road and was demolished, killing Ryan and passenger Zachary Hartwell. What caused it?

The road was likely deserted at 2:30 a.m. when the car slammed into a guardrail, flipped into a stand of trees and burst into flames. Or was it?

West Goshen Police Chief Michael Carroll told gossip site radaronline it was the worst crash he had ever seen.

Dunn was driving a high-powered 2007 Porsche 911 GT3 coup, which is a street version of Porsche’s race car.

It’s the lightest 911 made and capable of speeds close to 200 miles per hour.

Check out Ryan’s Twitter photos; click to enlarge.

High speed is responsible for the horrific nature of the crash. The car traveled through 40 feet of trees before exploding into flames.

“I’ve never seen a car destroyed in an automobile accident the way this car was even before it caught on fire,’ Carroll said. “The automobile actually came apart. It was unbelievable and I’ve been on a lot of fatal accident scenes. This is by far the worse I’ve ever seen.”

The car was so badly damaged and the bodies so disfigured, the coroner’s office could not tell whether the impact of the crash (likely) or the fire killed the two men.

The official cause of death was listed as blunt force trauma and thermal trauma. It will also take several weeks to determine what role, if any, alcohol played in the accident. The findings await the results of toxicology examination.

What is known is that both men were drinking in the hours before the crash, according to photos Dunn published on his Twitter account. Dunn drank at least three light beers and three shots between the hours of 10.30pm and 2.10am, according to TMZ, citing a source.

One of the most significant findings at the crash scene were skid marks from the car 100 feet long. They suggest the driver saw an obstruction in the road, which was straight, and tried desperately to slow down the car and take evasive action.

Whether it was another car, or possibly a deer, which are rampant in the area, is unknown.

At 130 miles per hour, the car would have been traveling at roughly 180 feet per second. If an object such as a deer suddenly appeared in the road, that means the driver slammed on the brakes less than a second before a possible impact.

A standard Porsche GT3 can go from 100 miles per hour to a full stop in 217 feet, according to road tests. That suggests the car could have been traveling faster than 130 miles an hour, given the force of the impact.

Porsches have four-wheel, anti-lock brakes, so it’s possible to maintain control of the car in an emergency stop, even at high speed. The driver possibly tried to steer around the object, since the skid marks point to the right shoulder.

But given the speed and reaction time, which could have been affected by alcohol, he may have misjudged the amount of room on the side of the road.

Or possibly, he couldn’t react quickly enough to steer clear of the guardrail, which sent the car careening into the trees. Whoever was driving forgot one of the most fundamental rules about driving a high-performance Porsche — never slam on the brakes.

Because the engine is in the rear, the centrifugal force from its weight, makes the car unstable and prone to spin in hard stops.

It’s safer to keep the power on, stay off the brakes and steer around the obstruction even at 130 miles an hour. That’s what a Porsche is designed to do.