CHICAGO (AP) -- A medical helicopter pilot hit bad weather and was trying to return to the hospital hangar shortly before the aircraft crashed into a northern Illinois field, killing him and two nurses, authorities said Tuesday.
Pilot Andy Olesen radioed to dispatchers at Rockford Memorial Hospital that he was turning around because he had "encountered some weather" while heading to another hospital to pick up a patient Monday night, hospital spokesman Wester Wuori said.
Olesen, 65, and flight nurses Karen Hollis, 48, and Jim Dillow, 40, died when the plane crashed about 8:30 p.m. near Rochelle, about 70 miles west of Chicago. No patients were aboard at the time.
The Federal Aviation Administration and National Transportation Safety Board are investigating.
National Weather Service observations showed light snow, seven-mile visibility and light winds in the Rochelle area around the time of the crash, meteorologist Jamie Enderlen said. She said the NWS usually worries about visibility of a mile or less, "but there could have been localized" weather at the point the helicopter turned around.
Wuori said he was not sure where the helicopter was when Olesen turned. It crashed several miles south of Rochelle.
The hospital issued a statement saying it was grieving for "three heroes who dedicated their careers to serving others."
"This is just a complete shock to everybody," Wuori said. "The crew ... worked with so many people."
Wuori said the hospital bought the helicopter in 1991 and it had a "perfect safety record up until last night." The hospital contracted with Colorado-based Air Methods for services, which included the pilot, maintenance and FAA certification.
The nurses were employed by the hospital.
Air Methods Vice President Craig Yale said the hospital's helicopter, an MBBK 117, was "a very reliable aircraft" and a "workhorse in our industry." He could not discuss the crash because of the ongoing investigation.
He also said that Olesen was an experienced pilot who had worked for the company for 19 years, after flying for the U.S. Army for 23 years.
"We are trying to recognize his professionalism," Yale said. "(Olesen) was a seasoned and professional pilot."
Rockford Memorial said Hollis was a critical care nurse who had worked at the hospital for more than 25 years. Dillow had worked there for 20 years with experience in critical care and in the emergency room.
Air Methods pledged its "full cooperation" with investigators.
"We extend our heartfelt sympathy to the family, colleagues and friends of those who perished in Illinois while on duty," Air Methods CEO Aaron Todd said in a written statement.
Yale said Air Methods is the world's largest medical air transport company. He said the company provides services to hospitals all over the country, and it was unusual for a hospital to own its own helicopter rather than contracting with the company for an aircraft.