Rockford Memorial Hospital's medical helicopter crashed on Monday night, killing three people on board. (Credit: Rockford Memorial Hospital)

Rockford Memorial Hospital’s medical helicopter crashed on Monday night, killing three people on board. (Credit: Rockford Memorial Hospital)

UPDATED: 12/11/2012 – 4:58 p.m.

ROCHELLE, Ill. (CBS) — A medical helicopter pilot and two nurses from Rockford Memorial Hospital were killed Monday night, when their chopper crashed in an empty field in Rochelle, Ill., about 80 miles west of Chicago.

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CBS 2’s Chris Martinez reports the crew was on its way to pick up a patient from a hospital in Mendota, Ill., at the time of the crash. Debris was scattered all over the cornfield, where crews spent the day Tuesday sifting through what’s left of the chopper.

Officials said, shortly after takeoff in freezing rain, the pilot radioed back that they had encountered bad weather and were turning around. A short time later – around 8:30 p.m. – that dispatch center received reports that the helicopter had crashed.

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The crew members were identified by Rockford Health System as pilot Andy Olesen, flight nurses Karen Hollis and Jim Dillow.

“This is a very, very close-knit family,” Rockford Health System President and CEO Gary Kaatz said.

They were, by all accounts, among Rockford Memorial Hospital’s very best; three veterans of the Regional Emergency Acute Care Transport (REACT) flight crew.

Dillow and Hollis both had 10 years on board. Oleson – a military veteran – had been flying the hospital’s helicopter for five years, and had worked for Air Methods – the owner of the helicopter – since the mid-1990s. He was just days from closing out his career.

“He was one week away from retirement. In fact, this weekend, they were supposed to have a retirement party for him in Chicago, with his family,” said Fr. Ralph Kuespert, pastor of Bethlehem Lutheran Church.

Wreckage of the medical helicopter that crashed near Rochelle on Monday night. (CBS)

Wreckage of the medical helicopter that crashed near Rochelle on Monday night. (CBS)

Kuespert came to know Olesen as a faithful member of the church, and a buddy on the golf course. Olesen was a grandfather.

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Hollis was a mother to two young girls.

It was those kinds of personal details the people they helped every day at work likely never knew, but that their larger family at the hospital couldn’t get off their minds.

“We definitely have a hole in our heart for our family members today, that are missing,” Rockford Memorial Hospital business manager Ron Meadors said.

The crash was the first accident in the hospital’s REACT program’s 25-year history.

“To have them lost on a mission where they were going to help somebody in need of our services adds to that pain,” Kaatz said.

Witnesses who live next to crash site said they’re used to hearing helicopters fly overhead, but last night, it didn’t sound right.

“All of a sudden, I see a red light coming out of the sky and nosedive and go right into the ground out here, and I thought holy cow there’s something out there,” said Michael Bernardin.

Paul Heiman, heard the crash: “We heard the next 2-3 seconds of the engine sputtering or cutting out … after those a 2-3 seconds it was quiet and then after that we heard a big thud like an impact, something hitting the ground.”

Dozens of investigators from the NTSB and the Federal Aviation Administration were combing the scene on Tuesday.

The helicopter involved in the crash was owned by Air Methods, the world’s largest medical transport company. The chopper was manufactured in 1992.

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Air Methods has a fleet of 400 helicopters. Since 1980 the company has had 12 fatal accidents. The last was in Missouri in August 2011, when one patient and three crew members died.