MADISON, Wis. (AP) -- Three people are dead after a University of Wisconsin Med Flight helicopter crashed after taking off last night from La Crosse.

Aaron Conklin says a surgeon, a nurse and the pilot were killed in the crash, which took place as the helicopter was returning to Madison from the Gundersen Lutheran Medical Center.

Allan Tiedt of the La Crosse County Emergency Dispatch Center says the wreckage was found in the town of Onalaska.

UW Hospital chief operating officer Margaret Van Bree says those killed in the crash were surgeon Darren Bean, nurse Mark Coyne and pilot Steve Lipperer.

She says the helicopter left Madison around 8:30 last night to drop off a patient at the La Crosse hospital and departed the airport there at about 10:30.

Van Bree says there was no further communication with the crew.

She says the helicopter was found about four miles from the airport at about 8:40 this morning.

Van Bree says preliminary reports indicate the helicopter may have struck a hill or some trees but the exact cause is not yet known.

Darren Bean received his medical degree from the University of Vermont College of Medicine in 1999, and completed residency training at Carolinas Medical Center in Charlotte, North Carolina.

Bean also was the emergency department director of ultrasound, and an assistant professor at the University of Wisconsin School of Medicine and Public Health.

Nurse Mark Coyne was a 22-year veteran of the Med Flight system and had worked for the hospital since 1981. He also was an emergency medical technician-paramedic.

Pilot Steve Lipperer worked for Air Methods and was a contract employee for the hospital system.

All three lived in Madison.

A second Med Flight helicopter leased by University of Wisconsin Hospital is grounded in the wake of the crash of one after it took off from La Crosse last night.

Med Flight director Mark Hanson says both have been leased from Air Methods in Denver.

He says that, if air service is needed while the helicopters are grounded, other helicopters being used by other hospitals may be used.

Hanson says neither helicopter had any mechanical problems since going into service.

But Hanson says the two helicopters, along with 21 other Air Methods helicopters, were grounded for a week earlier this year for paperwork issues that did not pertain to the structural integrity or reliability of the aircraft.

The copter model is American Eurocopter EC13.