FREDERICK, Md. (AP) — An airplane and a helicopter collided in the air near a Maryland airport before crashing into a line of trees and a self-storage business Thursday afternoon, killing three people but sparing two men in the plane, who deployed a parachute attached to the aircraft before it hit the trees.

The Cirrus SR22 plane was heading to the Frederick Municipal Airport and a Robinson R44 helicopter was engaged in a training exercise when the collision occurred near the southwest corner of the airport, the Federal Aviation Administration said in a statement. The statement did not say what kind of training exercise the helicopter was conducting or identify its owner. It said the FAA and National Transportation Safety Board were investigating the collision.

The helicopter was leased to Advanced Helicopter Concepts, a flight school at the airport, said Neal Lanning, the company’s owner. He said company officials would hold a news conference Friday morning.

The same company was the operator of a helicopter of the same make and model that crashed on Interstate 70 about 15 miles west of Frederick in 2009, killing all four people aboard. The NTSB ruled that crash an accident linked to poor nighttime visibility on a fog-shrouded mountain.

The plane went down in a stand of trees east of downtown Frederick, while the helicopter crashed a tenth of a mile south, between two storage units, said Maryland State Police spokesman Greg Shipley.

It was not immediately clear if the three people who died were all on the helicopter, or if someone on the ground was killed, Shipley said.

The two men on the plane were taken by ambulance to Meritus Medical Center in Hagerstown, but were discharged, hospital spokeswoman Joelle Butler said in an email about three hours after the collision.

Shipley said one of the men suffered a cut and the other was not hurt. State police investigators were interviewing them Thursday night, and the NTSB planned to, as well.

The parachute deployed from the plane following the 3:40 p.m. collision and was still attached to the aircraft when emergency responders arrived on the scene, said Capt. Kevin Fox of Frederick County Fire and Rescue. The large, red-and-white striped parachute could initially be seen still inflated and in the air, and then on the ground.

The plane appeared to be largely intact, while the helicopter was demolished.

The parachute that deployed is attached to the frame of the airplane and is designed to lower an airplane safely when the pilot is unable to, said Brian Rayner, a senior air safety investigator for the NTSB.

Rayner said the NTSB would interview the air traffic controllers at the Frederick tower, who were probably in control of both aircraft at the time. He said the helicopter appeared to be departing the city-owned, civilian airport.

Jesse Ault Jr. of Brunswick and his wife, Pamela, saw the crash as he picked her up from her job nearby.

“We headed around the corner to the Wendy’s drive-thru, I’m getting ready to pay, and she goes, ‘Oh, my God, there’s an airplane spiraling out of control.’ I looked over and saw the wing of a plane and what looked like a parachute. ... I saw some people tending to the pilot of the plane.”

He said the pilot was hurt and shaken up.

“The pilot had blood up above his nose and on his face,” Ault said. “You could tell he was visibly shaken.”

The weather was cloudy and breezy at the time, but didn’t seem to be a factor in the collision, Rayner said.

According to the FlightAware aviation tracking website, the plane took off from Cleveland Regional Jetport in Cleveland, Tennessee.

A tail number visible in aerial footage from WJZ-TV in Baltimore is registered to Graeves Auto & Appliance in Olney, Maryland. A woman who answered the phone at the store about 4:30 p.m. said, “We can’t give you any information” and hung up. According to the store’s website, Scott Graeves is the owner of the business. No one immediately responded to a telephone message left at his home.

The collision prompted road closures at rush hour around the airport near Interstate 70.