EL PASO, Texas — Three people were killed when a medical helicopter crashed during a training exercise at Fort Bliss, just outside El Paso, Army authorities said.

The Southwest Med Evac helicopter crashed on final approach to a landing zone Friday during a scheduled training session at the McGregor Range, according to a statement Saturday from Las Cruces, N.M.-based Southwest Med Evac, a unit of Addison, Texas-based Omniflight Helicopters.

The company said the three crew members on board were the pilot, William Montgomery of Avondale, Ariz., and paramedics John Sutter of Las Cruces, N.M., and Anthony Archuleta of El Paso, Texas.

Anthony DiNota, president and COO of Omniflight Helicopters, said the cause of the crash was not yet known.

"There are many questions that need to be answered," he said. "Right now, our focus is on the families who are experiencing this huge loss, and we are working with federal investigators to identify the cause."

Post spokeswoman Jean Offutt told the El Paso Times that the helicopter caught on fire.

At the time of the accident, the weather was clear and the pilot was in contact with military range control officers and the company's communication center, the company said. It added that the helicopter was equipped with night vision goggles for each crew member, satellite navigation, radar altimeter and GPS.

Friday was the second day of a two-day training scenario involving a simulated medical evacuation.

The newspaper said federal investigators including from the National Transportation Safety Board were on the scene.

Southwest Med Evac has a contract with Fort Bliss for emergency medical services.