The driver of a car was killed and several people in a bus were seriously injured Wednesday when a car and a commercial bus with 56 people on board collided east of Madison.

The 55 bus passengers and driver received a variety of injuries, Highway Patrol Lt. Alan Welsh said at a briefing.

Fifty-one people were taken to a hospital for treatment or hospitalization, according to the state Department of Public Safety.

Welsh said the most seriously injured were airlifted immediately to Sioux Falls hospitals. By late afternoon, 16 had been taken to Sioux Falls hospitals.

Welsh said a westbound car driven by Lance Parliament, 24, of Sioux Falls, drifted into the oncoming lane on Highway 34 and struck the bus on the driver's side.

The bus went into the ditch and traveled for some distance, then tipped on its side as it came to a stop.

Welsh said the excursion on the Reading Bus Lines bus was organized by J&R Bus Tours and originated in Mitchell on a trip to a casino in Flandreau. It picked up passengers in Mitchell, Artesian, Fedora, Howard, Madison and at the junction of Highways 34 and 37, the Department of Public Safety said.

The accident around 10 a.m. brought a rush of ground and air ambulances from the area.

Lake County Sheriff Roger Hartman, who was among the first responders, said some passengers were out of the bus and tending to other injured passengers when he arrived.

Emergency workers removed passengers from the bus through its escape hatches and broken-out windshield, Hartman said.

Avera McKennan Hospital in Sioux Falls was treating 10 accident victims at late afternoon and expected two more, a spokesman said. Of the 10, one was in critical condition and three were in serious condition.

Sanford USD Medical Center across town reported six patients from the accident - one in critical condition and two in serious condition.

A two-mile stretch of Highway 34 was closed for most of the day.