NEKIMI, Wis. (AP) — A plane crashed in a Wisconsin farm field near the site of an air show Monday, killing the two people on board, authorities said.

Sheriff’s deputies and firefighters responding to the crash in the eastern Wisconsin town of Nekimi on Monday afternoon found the aircraft fully engulfed in flames, the Winnebago County Sheriff’s Office said.

Authorities were not releasing the names of the people who were killed, pending notification of relatives.

The National Transportation Safety Board is investigating.

The plane crashed about 2 miles (3 kilometers) south of the site of the EAA AirVenture air show at Oshkosh’s Wittman Regional Airport. Monday was the first day of the 71st AirVenture, a weeklong event scheduled to include military aircraft demonstrations and forums with combat pilots, aircraft designers and NASA astronauts, the Oshkosh Northwestern reported.

The Associated Press left a telephone message with the EAA’s spokesperson on Monday afternoon.