A surgeon from a Mayo Clinic in Florida flying across the northern corner of the state to retrieve a heart for transplant was killed Monday when his helicopter crashed, officials said.

The heart could not be used in another transplant because its viability expired, and the patient who had been scheduled to receive it continues to wait for a new organ, Mayo Clinic spokesman Layne Smith said Monday evening.

The helicopter departed the clinic in Jacksonville around 5:45 a.m. but never arrived at the Gainesville hospital, Shands at University of Florida, about 60 miles southwest, said Kathy Barbour, a spokeswoman for Mayo, which is based in Rochester, Minn.

Heart surgeon Dr. Luis Bonilla, procurement technician David Hines and the pilot were killed.

The helicopter went down about 12 miles northeast of Palatka, said Federal Aviation Administration spokeswoman Kathleen Bergen. The town is about 40 miles east of Gainesville and about 45 miles south of Jacksonville.

Clay County Sheriff's Office dispatcher Myron White confirmed the three dead but had no more information to release about the crash in the remote, forested area away from roads. The National Transportation Safety Board also was investigating.

The National Weather Service in Jacksonville reported that there was light fog with overcast conditions in the area but no rain.

"As we mourn this tragic event, we will remember the selfless and intense dedication they brought to making a difference in the lives of our patients," John Noseworthy, Mayo Clinic president and chief executive officer, said in a statement. "We recognize the commitment transplant teams make every day in helping patients at Mayo Clinic and beyond. Our thoughts and prayers are with the families."

FAA records show the Bell 206 helicopter is operated by SK Jets. The St. Augustine company released a statement Monday evening: "The focus of our efforts at this time is to attend to the needs of our passengers, crew and their families and work with the NTSB and local public safety officials to determine the cause and extent of the accident."

The pilot's name was not released.

Gary Robb, a Kansas City aviation attorney specializing in helicopter safety, said SK Jets is known as a careful and safe operator in the industry. The small, lightweight craft has low weight and speed capabilities and is primarily used by traffic reporters or police departments, Robb said.

"It's not usually used in donor flights," he said.

An NTSB investigator will scour the crash site for clues and look into the pilot's experience and any factors that might have impaired the pilot, any environmental factors such as birds or low visibility that may have contributed to the crash, and any mechanical problems with the helicopter, he said.

The Bell 206 helicopter usually has an older engine no longer installed in new helicopters, Robb said.