The Mountain Home Air Force Base in Idaho was locked down Sunday following a midair collision during a local air show that sent two fighter jets crashing to the ground.

The incident occurred about 2 miles northwest of the base during the second day of the Gunfighter Skies Air Show, the base said on social media.

“Emergency Responders are on the scene, an investigation is underway and more details will be released as they become available,” the base said.

The base, home to the U.S. Air Force’s 366th Fighter Wing, known as the “Gunfighters,” announced the lockdown at 12:30 p.m. local time.

Video circulating on social media showed two fighter jets colliding midair before spinning toward the ground in a fiery crash amid black plumes of smoke. Four parachutes were visible deploying near the crash site.

Another video shared on Instagram showed spectators at an aircraft hangar surrounded by planes, and black smoke from the crash rising in the background.

“I heard someone next to me say ‘We are down,’ I turned around and saw four parachutes coming down, then black smoke appeared,” the witness who filmed the video told NBC News. “We are currently still on the airshow field and not allowed to leave at this time.”

“The atmosphere is very calm controlled and well managed right now,” they added, noting many present are military families.

Mountain Home police announced Sunday the air show was canceled and warned the public to avoid traveling to the base.

On Saturday, the base shared photos from Day 1 of the air show, writing: “From the first takeoff to the final pass, today was packed with unforgettable moments! And we’re doing it all again tomorrow.”

This is a developing story. Please check back for more information.