Five members of a motorcycle-racing family from Jordan were killed Sunday while returning from a Texas vacation when the motor home they were in plunged into a ravine off Interstate 35 in Kansas.

Another 13 people, including several other members of the Kerber family, were badly injured in the crash just outside Williamsburg, Kan., according to authorities and friends of the family.

"All day long, we've been hoping and saying a prayer or two," said John Marks, a close family friend of the Kerbers, a well-known family from the Scott County community.

The family, including mother Pauline Kerber, 46, a widow, and many of her 12 children, had vacationed in Texas for a week and participated in motorcycle races.

Investigators in Kansas said the motor home was a Freightliner box truck set up with living quarters. Authorities have not released the names of the dead, but friends have identified them as members of the extended Kerber family.

Marks, who described himself as a father and grandfather figure to the 12 Kerber offspring, said relatives told him that among the dead are Tom Kerber, 25, and his wife, Melissa, 24, as well as three of Tom's younger siblings, Joy, 14; James, 12, and Jessica, 10.

Marks said their brother Russ Kerber, 24, who did not go on the Texas trip, told him a younger brother and his mother, Pauline, were undergoing surgery Sunday for injuries.

"Russ called me and told me he had some bad news," Marks said. "I was kind of their grandpa and sometimes their dad. I will miss them horribly."

The crash happened about 9 a.m. on Interstate 35 in Osage County about 3 miles south of Williamsburg. The cause of the crash is under investigation, but the Kansas Highway Patrol said the vehicle hit a guard rail and then plunged off a bridge and into the ravine.

At least four of the 13 survivors were critically injured. They were taken to hospitals in Ottawa, Topeka and the Kansas City metro area. Three victims were in critical condition Sunday at Overland Park Regional Medical Center, said spokeswoman Christine Hamele. She said at least one other victim was critically injured.

Mary Mohn of Woodbury was first to reach the victims. She and a friend, both nurse practitioners, were driving behind the Kerbers while returning from a conference. They stopped when they saw skid marks on the road and a woman looking down the 30-foot ravine at the demolished motor home.

"I couldn't believe what I saw," Mohn said. "It looked like the RV exploded. The walls were on both sides of the creek. A couch was sitting in the creek. Toilets were on the embankment. Clothes and food and shoes were scattered all over. I could hear a woman screaming ... and kids whimpering, crying."

Mohn slid down the steep, rocky bank to triage the injured, and her friend Marsha Moreen stayed on the road talking via cell phone about the victims' conditions to dispatchers, who sent about eight ambulances to the scene.

Mohn said several truckers and others stopped to help before emergency workers arrived. They saw broken bones, head injuries and many scrapes and bruises. One rescuer carried two young girls out of a shallow creek to a bank.

Mohn said a teenager involved in the crash told her the family was returning to Jordan from a vacation in Texas where they had used dirt bikes and ATVs. Authorities have not said who was driving.

Kathy Lapic, another family friend, said the Kerbers often traveled out of state for motorcycle races, especially since one of the teen boys, Adam, was possibly on his way to a professional racing career. Adam was listed in critical condition Sunday in Overland Park.

"He had a lot of trophies," Lapic said. "They would travel frequently out of state."

Marks said the family bought the motor home and trailer about seven years ago, shortly before Glen Kerber, family patriarch, died at 43 from a rare tissue disorder. Pauline Kerber was pregnant with their 12th child at the time, friends said.

"Thank you for the outpouring love and support during this tragic accident. We appreciate the prayers of so many, and appreciate you respecting our privacy as we mourn our deep loss," said a statement late Sunday attributed by the Overland Park hospital to Pauline Kerber, listed in critical condition.

Neither Marks nor Lapic knew who else might have been traveling with the family, but said they were probably friends who were part of the family's motocross activities.

Marks said the family owned and operated an auto shop near their home, a business they took over after the father died in October 2006.

"They've had some terrible tragedy, and I'm sorry they have to go through something like this again," Lapic said. "They are a very, very close family."

At the western outskirts of Jordan Sunday night, family and relatives gathered at the Kerber home, where a swing set and trampoline stood silent. A dozen or so mourners gathered by the mailbox along 190th Street W., turning away reporters. "They're great, loving people; that's all I'll say," said one young man.

Across the road, cattle and horses grazed on the green hillside. Burdette Stief tended sadly to his livestock, talking of the family he's long known. "They'd help anybody," he said. "They're very nice people."

A few miles away, at a McDonald's, worker Britta Baker, 16, grieved. "They're all home-schooled and super nice," she said of the Kerbers, adding that the mom worked as a janitor at the local elementary school.

She told, too, of watching the Kerber boys race dirt bikes and motocross at the Scott County fairgrounds. It's a tragedy that shakes the entire community, Stief said. "Everybody knows everybody," he said.

Marks said he is awaiting word to find out what else he can do to support the family.

"We had a wonderful relationship," he said. "Whenever you needed something, all you had to do was ask them. The father was like that, and so are the kids. We've been together a very long time."

Staff writer Joy Powell contributed to this report. • 952-746-3281 • 952-746-3283