(CNN) -- At the intersection of the two country roads, charred debris lies strewn haphazardly. The earth around it is scorched.
It is here, in this corner of Dumas, Texas, that a sport utility vehicle and a gas tanker collided Sunday afternoon. The tanker's flammable cargo sent both vehicles up in flames, seriously injuring the truck driver and killing all five passengers in the Chevrolet SUV.
All of those who died were teenagers.
The crash, coupled with another one in Warren, Ohio, the same day, highlight that motor vehicle wrecks continue to be the No. 1 killer of youths in the United States.
Such accidents took the lives of about a quarter of the 15- to 24-year-olds who died in 2010, according to the most recent numbers from the Centers for Disease Control and Prevention.
They outpaced the other top culprits: firearm wounds, homicides, suicides and accidental poisonings.
But the wrecks mask a broader improvement: Overall traffic fatalities have been dropping in a "historic downward trend," according to the National Highway Traffic Safety Administration. In 2005, it tallied 43,510 traffic deaths; in 2011, there were 32,367, the lowest level since 1949.
In 2009, motor vehicle crashes were the 11th-leading cause of death. That marked the first time since 1981, when data were first available, that motor vehicle crashes were not among the nation's top 10 causes of death.
A fatal mistake
It wasn't clear where the teens were headed in the SUV when, authorities say, the driver, 16-year-old Jacob Paul Stipe, failed to stop at a stop sign.
It was a fateful mistake.
As the SUV entered the intersection, a truck smashed into its passenger side, CNN affiliate KFDA reported, quoting authorities.
Paul died at the scene. So did his four passengers: October Dawn Roys, 17; Elizabeth Kay Roys, 15; Derrek Lee Hager, 17; and Christopher Lee Moore, 17.
The truck driver, Ezequel Melecio Garcia, was flown to a hospital burn unit in Lubbock.
Best of friends
The teens were friends, said Star Tovar, assistant manager at the local Dairy Queen.
"It was always them together, all five of them always together," she told CNN affiliate KVII.
Chris had recently moved to the area.
Elizabeth and October, who went by the nickname Toby, were sisters. October leaves an infant daughter.
Their parents, Robert and Sheryl Roys, wept as they spoke to the affiliate.
"They changed hair color every month," Robert Roys said, smiling for a moment.
"It's going to be hard not having them around because they were there all the time. I love them with all my heart and they'll always be here, in my heart," said Sheryl.
Grief in Ohio
Hours earlier and nearly 1,400 miles away, in Warren, Ohio, six teenagers were killed when an SUV struck a guard rail and flipped into a pond.
They were among eight teens who had crammed into the Honda Passport, which was later reported stolen. It was built to seat no more than five.
None of the dead had been wearing a seat belt, authorities said.
The teenagers were speeding down a two-lane northeastern Ohio road, authorities say.
Alexis Cayson, 19, was behind the wheel, the highway patrol said.
Those who died alongside her were: Andrique Bennett, 14; Kirklan M. Behner, 15; Daylan Ray, 15; Brandon A. Murray, 14; and Ramone M. White, 15. All were from Warren.
The two survivors escaped by breaking the rear window in the submerged vehicle, Ohio State Highway Patrol Lt. Brian Holt said. They ran a quarter mile to a nearby home and called 911, he said.
Holt said weather was not a factor in the wreck -- the deadliest in his county's history and the worst in Ohio in at least three years.
Monday night, mourners held a vigil near the guard rail and alongside a makeshift memorial of Teddy bears and a cross.
They released helium-filled balloons into the air to commemorate the dead.
"It's numbing. It's confusing. It's hurtful," said Charlene Blackwell, whose nephew Ramone White was among the dead.
Grief counselors visited area schools Monday to help students and staff with the emotional aftermath.