Two small single-engine planes collided midair on Wednesday morning at an Arizona airport, resulting in the deaths of at least two people, according to officials.

The Federal Aviation Administration reported that a Lancair 360 MK II and a Cessna 172S crashed just before 8:30 a.m. local time at Marana Regional Airport, which is located approximately 21 miles northwest of Tucson. The airport is an uncontrolled field, meaning it does not have an active air traffic control tower.

Marana police confirmed on Facebook that officers responded to the crash site. The National Transportation Safety Board will take the lead in investigating the incident.

Preliminary findings indicate that the “aircraft collided while upwind of runway 12,” according to an NTSB statement. The Cessna was able to “land uneventfully,” while the Lancair crashed near runway 3, where it caught fire upon impact.

Both planes were carrying two people each, but no further details were immediately available.

At airports without air traffic control towers, pilots rely on a common traffic advisory frequency to communicate their positions and ensure safe operation in the area. The pilot-in-command is responsible for maintaining a safe distance from other aircraft.

Even in uncontrolled airspace, pilots must still adhere to all federal aviation regulations, including minimum visibility requirements, safe altitude standards, and right-of-way rules.

This collision is part of a series of recent aviation accidents. These include a fiery crash-landing at a Toronto airport, a fatal air ambulance crash in Philadelphia on January 31, and a devastating midair collision between an Army helicopter and a commercial airplane. The latter incident resulted in the deaths of all 67 passengers on both aircraft, marking it as the deadliest U.S. aviation accident in nearly 25 years.