CHICAGO -- Seven people were killed in a plane crash near Bloomington Airport in McLean County of the US state of Illinois early Tuesday morning, according to a statement released by the McLean County Sheriff's Department.

Air traffic controllers lost contact with the small Cessna 414A aircraft shortly after midnight, the department said, adding that three hours later a police officer with the Bloomington Police Department found the aircraft crashed in a field near the airport as controllers notified local authorities.

The Bloomington Airport was not manned at the time and air traffic control services for the flight were based in Peoria, the county seat of Peoria County, it said.

The weather was foggy at the night of the crash, but the lights used to guide airplanes safely to the runway were functioning properly, according to local media.

US Federal National Transportation Safety Board (NTSB) and Federal Aviation Administration (FAA) investigators have been on the scene to investigate.

All 7 people on board the crashed plane have been identified. Among them, 37-year-old Aaron Leetch and 36-year-old Torrey Ward who worked for the Illinois State University athletics department were returning from the National Collegiate Athletic Association (NCAA) Basketball Championship held in Indianapolis, Indiana.

Leetch was deputy director of athletics for external operations, and Ward was associate head coach of the school's men basketball team, according to the University.