Four children drowned when a wall of water swept over the Kansas Turnpike (search), dragging their family's minivan more than a mile as their father tried desperately to pull them to safety. Their mother and another motorist were missing.

Meanwhile, in suburban Kansas City, authorities on Monday found the body of an 18-year-old who was missing after he went swimming in a rain-swollen creek.

The four children — all under age 10 — were found dead, three of them still strapped into the mangled minivan in Emporia (search), southwest of Kansas City. The search for their mother, as well as a man missing from a separate vehicle, resumed Monday morning.

The search was focused on a rain-swollen reservoir three miles south of the turnpike behind a dam, fire officials said. More than 50 people, in boats and walking the shore, were working their way from the earthen dam back toward the turnpike as the water slowly began to recede.

The family's vehicle and five other vehicles were washed off the roadway late Saturday in eastern Kansas when torrential rain sent a creek spilling over Interstate 35, authorities said. Everyone on the other vehicles was accounted for.

"It happened really fast, there was nothing that could be done," said the Rev. Steve Gordon, a driver who escaped unharmed. "It was a sick feeling just watching them go under."

Elsewhere in eastern Kansas, authorities found the body of a suburban Kansas City teenager who was swept away while attempting to swim in the creek in Overland Park (search), a suburb of Kansas City. Two friends swimming with him were pulled to safety Sunday, authorities said.

The father of the children who drowned near Emporia, a resident of Liberty, Mo., told Trooper Marc McCune he broke out the driver's side window of the minivan and was sucked out. The van kept filling with water and floated away, McCune said.

"He knew his family was still in the van with the water," McCune said. "It's the most helpless feeling I've had in my life."

The minivan was found 1 miles from the scene with three children still strapped in. The fourth child was found Sunday morning about a quarter-mile from the van.

Police had not released the names of the victims but The Wichita Eagle identified the parents as Robert and Melissa Rogers, of Liberty.

The only other person who had not been accounted for was a man from Fort Worth, Texas, identified by the Eagle as Al Larsen, 31. Capt. Mark Conboy of the Kansas Highway Patrol (search) said the man had called his wife Saturday evening, told her his Jeep had stalled and asked her to come get him. The wife, who arrived Sunday morning, has not heard from him since.

"We believe he got out first and was out trying to help people," Conboy said. "That was just based on what he told his wife."

Light rain fell while search crews worked Sunday, following a downpour of more 8-12 inches in a 24-hour period starting early Saturday. Conboy estimated the water was six to seven feet deep along the section of interstate.

The flooding washed out chunks of the interstate and swept some of the heavy concrete barriers — which weigh between 10,000 and 12,000 pounds — 50 to 60 yards from the roadway, and the abandoned vehicles could be seen strewn about the valley.