Rescue teams in Alaska are continuing their search for a U.S. airman whose kayak overturned Friday evening on the Chena River in Fairbanks.

Staff Sgt. Christian Diaz, 24, of the 35th Fighter Generation Squadron at Kunsan Air Base in South Korea, was deployed to Eielson Air Force Base for training, according to statements from the 8th Fighter Wing and Fairbanks’ fire and police departments.

Diaz was kayaking with three friends near the Pioneer Park boat launch when his vessel capsized around 6:40 p.m., said the Fairbanks statement released Saturday. He was not wearing a life jacket.

Firemen responded quickly and launched an extensive search Friday evening, which has since transitioned to a recovery mission, the statement said.

“Our thoughts are with the friends and family of the missing man during this difficult time,” the unsigned statement said.

The wing confirmed in a Facebook post Sunday that Diaz, whose family has been notified, is part of a contingent deployed to Eielson for Red Flag — large-scale, multinational air combat training held multiple times each year.

Fairbanks officials urged people to use caution on or near the Chena River.

“Conditions can be unpredictable and potentially dangerous, even for strong swimmers,” the police and fire departments said in their joint release, emphasizing the importance of wearing a U.S. Coast Guard-approved life jacket.