Federal aviation investigators said they have determined that it was a 17-year-old — and not a much younger child — who started a helicopter while the aircraft was on display over the weekend during an air show near Mankato, a U.S. agency spokeswoman said Tuesday.

The additional information from the Federal Aviation Administration (FAA) raises the possibility that more than one person was in the helicopter at the time.

On Saturday, the rotor blades of the Mayo Clinic medical emergency helicopter unexpectedly began whirring at the Minnesota Air Spectacular at the Mankato Regional Airport. The sudden blast of wind knocked over a large sun shield on the tarmac, and two people were hit and slightly injured.

A worker at the show video-recorded a portion of the brief time when the helicopter was roaring and said he saw a Mayo aviation employee remove a crying boy from the aircraft. Agro Gushwa, 15, estimated that the boy was 6 years old.

On behalf of the FAA, spokeswoman Elizabeth Isham Cory said its agency has “confirmation the 17-year-old was the person at the controls, and … nobody else was in the cockpit.” Cory did not specify the teen’s gender.

Neither Cory nor Mayo Clinic Medical Transport spokesman Glenn Lyden has ruled out the possibility that more than one person was in the helicopter. Along with the cockpit, the aircraft has space in back that can be configured for up to nine people.

Cory said the FAA is investigating the incident and its probe could last for weeks.