Down a rocky tractor path, through a meadow whitened by the snowy heads of Queen Anne's lace and just beyond a towering wall of corn on a Frederick County farm, lies a dirt-bike rider's paradise.

Disappearing in a secluded stand of trees, the path snakes over a muddy daredevil course of single jumps, double-dip ramps and turnabouts crisscrossed by the tracks of deer hooves and off-road machines.

It was there that Benjamin M. Barr and his friend Justin Craigie, two teenagers aboard powerful, 400cc four-wheelers, spent hours riding Monday afternoon. Then, around dusk, as Ben roared out of the woods and Justin rounded a curve beside the cornfield, the two friends who considered themselves almost brothers collided head-on at such high speed that witnesses saw debris fly into the air.

"I came around the corner of the cornfield, saw him straight ahead and locked up my brakes," Craigie recalled Friday during an interview at his home. "I just remember right before I hit him. Then I blacked out."

Barr, 16, whose smile captivated friends and adults alike, died hours later in a Baltimore shock-trauma center.

For a time, Craigie's parents, Kenneth and Janet, thought their 17-year-old would die. The crash split his sternum from top to bottom, broke his right eye socket and fractured two vertabrae in his neck. For a day and a half, he lay unconscious.

On Wednesday night, however, Craigie left the same hospital. Still dressed in his hospital gown, his right eye stitched and bruised, a plastic brace clamped around his neck, Craigie returned to the spot near the accident where friends had strewed letters, balloons and flowers in a roadside shrine.

Only this time, the tractor path and the meadow were crowded with perhaps 150 people, mostly teenagers from Urbana High School. They followed the rocky trail by the light of luminarias, then stood in silence with lighted candles during a memorial service for Barr.

"Ben was a wonderful kid, a very special boy," said neighbor Jo Ostby, 49. "He was a great friend. He had the best smile you could imagine. He was the kind of kid who would come in the house and talk to the parents."

As friends and family members mourned him, however, some also wondered whether the teenagers should have been riding there without supervision, or riding such powerful machines at all. Barr's death comes at a time when federal officials are seeking to improve the safety of the increasingly popular vehicles.

The four-wheel, all-terrain vehicles, which are also known as quads or ATVs, have become common, particularly in rural areas where they double as gas-powered workhorses and off-road toys. There are now an estimated 6.2 million in use.

But as sales of the four-wheelers have grown, the numbers of deaths and injuries also have risen. The U.S. Consumer Product Safety Commission says 5,800 people died in ATV accidents from 1982 to 2003. Nearly a third of the injuries and fatalities involved riders who were younger than 16 riding adult-sized machines.

In the past month, for example, a 7-year-old girl was killed in eastern Pennsylvania, a 16-year-old boy died in Logan, W.Va., and an 11-year-old boy died in Cook, Minn., while riding ATVs.

A little more than a year ago, 11-year-old Zachary Beard of Boonsboro, Md., and 8-year-old Cody Pollard of Woodbridge, Va., were killed, and another 8-year-old boy was seriously injured, while riding ATVs near Zachary's home in Washington County.

The commission, which forced manufacturers to quit making three-wheeled ATVs in 1988, has prodded them to do more about safety. In June, its chairman directed staff to do a "top-to-bottom" review of ATV safety standards.

"I think our perspective at the CPSC is that there are certain behaviors that, if changed, could save lives," spokesman Scott Wolfson said.

The ATV Safety Institute, a division of the Specialty Vehicle Institute of America, counters that 92 percent of all ATV accidents involve misuse: allowing children to operate adult-sized vehicles, failing to use a helmet or driving the machines on roads. Even so, the group says the rate of injuries declined by 6.2 percent from 2001 to 2003, and by 32 percent between 1988 and 2002.

The group -- whose members include Honda, Kawasaki, Yamaha, Suzuki, Arctic Cat and other manufacturers -- offers cash incentives to new purchasers to complete free training courses.

In an interview Friday, Tim Buche, Specialty Vehicle Institute president, said the organization, based in Irvine, Calif., believes that further federal regulation targeting dealers would not be as effective as stricter laws at the state level that would allow law enforcement officials to target unsafe behavior. Ultimately, Buche said, the machines' owners, particularly parents, must be responsible.

"You could say, 'Kids will be kids,' but it's important to note that all of these machines have keys. That supervisor who controls the key controls the use of the machine," Buche said.

Monday's accident occurred near Route 355 and Reels Mill Road about 8:15 p.m., Frederick County Sheriff's Office spokeswoman Jennifer Bailey said. Craigie was driving a 2004 Arctic Cat. Barr had a 2005 Suzuki QuadSport 400. Neither had passengers, though two other teenagers were with them, including one with an ATV, according to Bailey and family members.

Both teenagers were wearing helmets, but neither helmet had been strapped on, Craigie said.

A few neighbors said they had complained for years about dirt bike and ATV drivers zooming through the fields and woods near the accident site, sometimes without helmets or on paved roads.

"Our concern is, this could have been avoided," neighbor Sandra Hevner, 52, said. "We talked to the parents. We talked to the kids. We talked to the landowner. We talked to the sheriff's office, and they all blew us off."

Clyde Stup, 51, another neighbor, said he had complained to Craigie's parents.

"One of these days, you're going to be visiting your son at the hospital, because he was driving without a helmet," Stup recalled telling them.

But Ken and Janet Craigie say the boys were well-mannered, responsible teenagers who just happened to love anything with a motor.

"You try telling a 17-year-old he can't do what he wants to do," said Ken Craigie, 40, an information technology administrator. "We had certain rules. Justin was a very good rider. They also wore helmets."

Barr and Craigie became friends in eighth grade. They both liked country music and AC/DC, and they liked riding dirt bikes. They became closer after Nancy Barr, a single mother who works in a pet supply store, moved from Urbana to a mobile home in Jefferson.

Nancy Barr did not respond to an interview request left at her home.

Instead of transferring to another high school, Barr continued attending Urbana, and he virtually moved in with the Craigies. But he also was devoted to his mother. He was happy when he got a job at Sears in Francis Scott Key Mall because, he told friends, it would allow him to help his mother. He persuaded Justin to work there, too.

"Ben's money clip, sneakers and clothes are still upstairs," Ken Craigie said Friday. When Barr got his school pictures, for example, he told the Craigies: "Hey, I'm one of your kids, too," and put it on the refrigerator, Ken Craigie said.

Both boys were "motorheads" eager to learn more about fixing cars, proud of the unique paint job they put on a used Jeep. When the paint did not turn out right, the boys sprayed on a synthetic plastic used to line pickup truck beds, giving the machine an oddly reptilian look. This spring, Barr drove his prom date in it.

Ashley Grisez, a Sears co-worker, said she had mentioned to Barr that, as a single mother, she had missed her prom. Barr invited her to his, and they went as friends in the painted Jeep.

"I think a lot of people have the what-if's, but they weren't irresponsible at all," Grisez, 22, of Urbana, said. "It was something they both loved, and they were doing what they loved doing."

Benjamin Barr, 16, was "a wonderful kid, a very special boy," a neighbor said.Friends and classmates of 16-year-old Benjamin Barr join in a candlelight vigil at the site where he was killed in a four-wheeler crash. Justin Craigie, the friend with whom he collided, survived.Mourners gather at the site where Benjamin Barr and Justin Craigie crashed on their four-wheelers. "It was something they both loved," a friend said.Justin Craigie, left, and Benjamin Barr were friends who considered themselves almost brothers.