The deaths of two people were reported after a Piper PA-32 plane crash at a small airport in Marana, Arizona, officials said Wednesday. Marana Mayor Jon Post said the aircraft went off the runway and burst into flames.

Marana Police Department officials said there were two people on board the plane and that the victims had not been identified. They said no other injuries were reported and no other aircraft were involved in the crash.

The National Transportation Safety Board said it has begun investigating the accident. The agency’s probe will examine what led to the plane leaving the runway and the circumstances around the fiery crash, officials said.

Marana, where the crash happened, is about 20 miles (32 kilometers) northwest of Tucson.