Two helicopters carrying a total of three people collided in mid-air Thursday near a small airport southwest of Portland, Oregon, forcing the closure of a key highway, authorities said.

Emergency crews responded around 2:15 p.m. following reports of a crash a few miles east of the McMinnville Airport, according to the Yamhill County Sheriff’s Office. Officials had no details about the occupants’ conditions.

One of the aircraft came from the aviation school Jerry Trimble Helicopters, which is located at the airport.

“Our hearts and thoughts are with the individuals involved, their families, and everyone affected by this event,” the school said in a statement posted on social media.

The school, which offers everything from demo flights for first-time flyers to advanced training, said it is cooperating with law enforcement along with the Federal Aviation Administration and National Transportation Safety Board to secure the site and determine the cause of the collision.

The FAA said the collision was between a Robinson R22 and an Airbus H125. Only the pilot was on board the R22 and the H125 was carrying two people, according to an FAA statement.

Photos posted by local media show a helicopter crumpled in a field near a road where caution tape has been hung up.

The Oregon Department of Transportation said Highway 233 is closed 1 mile (1.6 kilometers) west of Dayton because of the crash. There was no estimate for reopening.

Local roads were also closed. The sheriff's office urged the public to stay clear of the area.

The FAA and NTSB will investigate.

The R22 is a two-seat aircraft and the H125 can carry up to six passengers, depending on the configuration.

McMinnville, about 35 miles (56 kilometers) southwest of Portland, is home to about 34,000 people.

The small airport situated on 650 acres (263 hectares) has two paved runways and remained open Thursday, according to its website. It’s partially bordered by homes and near the North American Aerospace Museum.