— Four people were killed Friday when a Duke Life Flight medical helicopter crashed in northeast North Carolina, according to the State Highway Patrol.

The crash occurred in a grassy field near Amazon's wind farm outside the town of Belvidere, south of the Perquimans-Gates county line.

The helicopter, which was based at Johnston Regional Airport in Smithfield, was en route to Duke University Hospital in Durham from Sentara Albemarle Medical Center in Elizabeth City when it went down, officials said. A pilot, two medical personnel and a patient were aboard at the time, officials said.

On Saturday, Duke Hospital identified the staff members as flight nurses Kris Harrison and Crystal Sollinger and pilot Jeff Burke. The name of the patient on board was not released.

"We are deeply saddened by the loss of our patient and the dedicated professionals from Duke Life Flight," Albemarle Medical Center President Coleen Santa Ana said in a statement. "We extend our deepest condolences to the family and friends of the patient who was lost and to those closest to the crew members. We also extend our sincere sympathies to Duke University Medical Center on the loss of their colleagues. This tragedy reminds us of the devotion of healthcare professionals to the service of others."

The Life Flight program has been grounded until further notice, Duke University Hospital President Kevin Sowers said.

"How do you get back on the copter and fly again and how do you get back out into the field after going through a loss like this," he questioned.

Investigators with the National Transportation Safety Board went to the crash site Friday afternoon to assist with the investigation into the cause of the crash. Sowers said Duke is cooperating with investigators.

"We have no idea at this time and we will cooperate with the NTSB on the investigation, but we have no idea what happened," Sowers said.

Sowers said counselors were available at Duke Hospital to help staff cope with the deaths and hospital leaders said they are supporting the families of those who died in any way they can.

"The men and women of Duke Life Flight put their lives at risk every day to go bring critically ill patients back to this hospital," Sowers said. "We are very saddened by our loss today."

Duke operates two Life Flight helicopters, both of which are 5 years old. They fly to all of North Carolina and to parts of South Carolina, Virginia and Tennessee.

Life Flight also had a fatal crash in October 2000.

In that crash, the pilot instructed the crew to take a patient from Alamance Regional Hospital to Duke Hospital on the ground after seeing a warning light indicating a problem with transmission oil pressure. The helicopter crashed in a Burlington neighborhood shortly after takeoff as it was returning to Durham, killing the pilot.