TIFFIN - Adam Ports and three friends from Tiffin University thought it would be fun to ride out into the country, set an old chair afire, and toss it off the end of a pickup.

But the stunt turned terribly wrong when Mr. Ports, a freshman at the school, fell from the truck's bed and suffered fatal head injuries, authorities said yesterday.

"I don't know what they were thinking at that time," said Maj. Tim Thwaits of the Seneca County Sheriff's Office.

Mr. Ports, 18, of Wooster, Ohio, died Wednesday evening at St. Vincent Mercy Medical Center in Toledo, where he was taken after the Tuesday night accident.

The stunt may have been inspired by the television show Jackass, according to an incident report from the Seneca County Sheriff's Department. In the program, which has been turned into a hit movie, participants perform daredevil stunts such as setting themselves on fire.

The report, written by Sgt. Brian Hescht, states that Mr. Ports and three other students - Ryan Monahan, Steve Barnes, and Chris Bear - "had an old chair in the bed of the truck, and their intentions were to take the chair out somewhere and set it on fire. They were trying to create some type of stunt like they have on the TV show Jackass, on MTV."

Several teenagers across the nation have been injured trying to copy the show's stunts. But according to Major Thwaits, Mr. Ports and his friends were not mimicking Jackass.

"They were trying to create their own stunt, but they were not doing anything they had previously seen on that program," he said. Major Thwaits said detectives are still investigating what happened.

In a statement, a spokesman for MTV/Paramount said the television show and movie played no part in Mr. Ports' death.

"The police report that was filed makes it clear that this incident has no connection to any stunts performed on the Jackass television show or film," Marnie Malter said. "The stunts in Jackass have been performed by professionals, planned in advance and done with all appropriate safety precautions. And we have gone to great lengths to make sure the audience understands that they should not try these stunts."

Robert Thompson, a professor of popular culture at Syracuse University and director of the Center for the Studies of Popular Television, acknowledged that the program has been blamed for several accidents nationwide.

But he cautioned people not to be too quick to blame Jackass or the entertainment industry in general.

"It's so strange to me that whenever anything like this happens, the first comment is, 'It's Jackass' fault,'" he said. "When in the end, we have to remember that Jackass didn't set the thing up, and it didn't make them do it."

According to the sheriff's department report, the stunt occurred on Hopewell Township Road 123. Mr. Ports and Mr. Bear were in the truck's bed, Mr. Barnes was in the passenger seat, and Mr. Monahan was driving. A group in another vehicle followed them to photograph the stunt.

Major Thwaits said the department turned over a digital camera to the state Bureau of Criminal Identification and Investigation to see if any images could be recovered from it.

Mr. Ports' friends said he and Mr. Bear lit the chair with hair spray and a lighter, then kicked it off the back of the moving pickup. Mr. Barnes told Sergeant Hescht that Mr. Ports took a running leap out of the truck as it sped away at roughly 40 mph.

But Mr. Bear told the sergeant that Mr. Ports lost his balance and fell as Mr. Monahan accelerated away from the burning chair.

Mr. Ports' friends took him to the emergency room at Tiffin Mercy Hospital, arriving at 10:50 p.m. Seven minutes earlier, the sheriff's department received a 911 call from a man who said his friend had suffered a head injury at the Tiffin University soccer complex.

"We're rushing him to the hospital right now," the caller said. "We need to tell them he's on his way. He's got a serious head injury, and we're trying to get through town as fast as possible. He is not doing well."

The dispatcher asked how the person hurt his head, and the caller replied, "We were going to go to Wendy's, and he was going to jump in the back of the truck and didn't know the truck was going to move, the driver didn't know he was going. He jumped in and he caught his foot and he slipped and bashed his head on ... the sidewalk."

When initially questioned by Sergeant Hescht, Mr. Barnes and Mr. Monahan repeated that they had picked up Mr. Ports up at the university's soccer facility and that he fell from the truck there. But both later acknowledged that Mr. Ports was injured on Township Road 123 during the stunt.

Yesterday, students who knew Mr. Ports said they were stunned by his death.

"I never thought of him to do anything like that," said freshman Ashley Sullivan, who was in several classes with Mr. Ports. "I don't know how to handle it because I've never had a classmate have this happen to them. I feel terrible for his parents because their son goes away to school and they don't get to see him again."

In a campus office building yesterday, a group sat writing their memories of Mr. Ports on paper decorated with smiley-face stickers. One of the students, freshman Tiffany Hash, recalled Mr. Ports as a warm, fun-loving friend.

"He was a caretaker," she said. "He took care of everybody else. I don't know how many times he let me cry on his shoulder."

Miss Hash said she talked to Mr. Ports every day. "Today, out of force of habit, I dialed his number," she said. "I hung up when I realized what I had done."

Walter Zielinski, the university's vice president for student affairs, said counseling has been made available for students. He said he and Stephanie McLemore, the university chaplain, have spoken to the students who were with Mr. Ports when he was injured.

"We have talked to them, and they've not violated any university policies," he said. "We got them together in a room and said, 'We want to help you through this grief process.'"

A memorial service has been planned for Mr. Ports at 3 p.m. today in the Osceola Theater on campus.

Blade Staff Writer Erica Blake contributed to this report.

First Published November 22, 2002, 11:55 a.m.