An elderly man's apparent heart attack caused a chain-reaction crash that killed a pedestrian and narrowly missed a pregnant woman and two children yesterday afternoon on Stockton Road.

From the passenger seat, Robert Kolp's wife tried to control their white Chevy Lumina at speeds between 80 and 90 mph as it careened up the road near the Sonora Gold Lodge. Robert Kolp, 86, was unconscious and his foot continued to depress the gas pedal as the car clipped a school bus that had just dropped off its last students.

With Loretta Frances Kolp trying to steer, the car crossed the westbound lane and struck Aimee Louise Eaton, 27, of Sonora as she walked west along the road with her friend about 2:45 p.m.

Eaton was thrown about 100 feet into the air, and landed on a brown pickup parked in front of McCoy Tire Company. She died at the scene.

Robert Kolp and his wife, both of Columbia, were taken to Sonora Community Hospital, where he died. Loretta Kolp, age unknown, was stable this morning, a hospital spokesman said.

Eaton's friend, Wendy Flannery, 29, of the Sonora area, is pregnant and was pushing two infants in a double stroller. The women were out for a walk in hopes of inducing Flannery's labor, said California Highway Patrol Officer Tom Wills. Flannery told officers she felt the wind the Kolps' car created as it passed by.

Jeremy Diede, a mechanic at the tire shop, was just about to grab something out of a Tuolumne County sheriff's sport utility vehicle waiting to be picked up when he saw the commotion.

"I heard a noise and looked up and a body flew over my head," the 21-year-old Sonora man said.

The speeding Chevy first nicked a Sonora Elementary School bus that had just turned east from Southgate Drive at the entrance to the Mother Lode Fairgrounds. It struck Eaton, then hit seven other unoccupied cars, six of them in the McCoy Tire parking lot and one parked for sale on the side of the road.