TOWN OF HAZELHURST, Wis. - A medical transport company is suspending operations after a pilot and two medical crew members died in a helicopter crash in northeastern Wisconsin Thursday night.

A chopper contracted by Ascension Wisconsin went down in Hazelhurst, in a wooded area south of Minocqua in Oneida County. The company says air and ground ambulance service will be suspended until the company determines when it's appropriate to resume operations. Ascension said in a statement that it's working with emergency service partners and medical transportation colleagues in the region to meet patient needs.

The helicopter, a Eurocopter AS350, crashed while returning to a hospital in Woodruff after transporting a patient to Madison, according to Peter Knudson, a spokesman for the National Transportation Safety Board.

The helicopter lost contact with a GPS tracking system used by the operator at 10:43 p.m., Knudson said, and crashed in a wooded area near the Bearskin State Trail and South Blue Lake.

Authorities in northern Wisconsin say the three people killed in the crash of a medical helicopter were flight crew members.

The crash happened about 12 miles south of the medical helicopter’s destination, according to Tony Molinaro, a spokesman for the Federal Aviation Administration.

An NTSB investigator was expected to arrive at the crash scene Friday afternoon to document the site and collect evidence, Knudson said.

The Oneida County Dispatch Center got a call about the missing helicopter at 11:22 p.m. The last known contact with the helicopter was at 10:55 p.m., the sheriff’s office said. A crew of emergency responders searched the area and found the helicopter in the town of Hazelhurst.

A search was launched after the chopper was reported missing late Thursday night.

ThedaStar, an air medical service operated by ThedaCare, released a statement Friday morning about the Spirit Air Medical crash.

"We at ThedaStar are profoundly saddened by the loss of the valued emergency medical services colleagues and friends at Spirit," the statement said. "We are a small, close community and this affects the entire Wisconsin air medical family."

This isn’t the first time a medical helicopter crash in Wisconsin has resulted in fatalities.

At least four people have died in medical helicopter crashes in Wisconsin since 2006, according to a review of a National Transportation Safety Board database by USA TODAY NETWORK-Wisconsin.

A surgeon, nurse and pilot died when a University of Wisconsin Hospital Med Flight crashed May 10, 2008, after refueling and taking off from La Crosse, the Associated Press reported at the time.

A pilot died after a County Rescue helicopter crashed April 13, 2006, during a maintenance flight in Bellevue, according to a Green Bay Press-Gazette report.

The story will be updated as more information becomes available.