Updated at 9:35 a.m.: Revised to include that Willie has been found.

After a search that lasted more than 12 hours, a four-legged Fort Worth firefighter that got loose Monday has been found.

Willie, an arson detection dog for the Fort Worth Fire Department, went missing around 8 p.m. The Fort Worth Police Department tweeted around 9 a.m. Tuesday that he was discovered in someone's back yard.

He got loose near North Crowley High School at 9100 S. Hulen St., and kicked off an intense search for him, Fort Worth Fire Department spokesman Mike Drivdahl said.

Have you seen me? On 9-10-18, 1 of FWFD’s Arson detection dogs got loose and has not been found. Willie was last seen near North Crowley High School. He is a yellow lab and is wearing a blue collar with a brass name tag. If you have seen him please contact FWFD at 817-392-3000 pic.twitter.com/lHTjY5EXwY — Fort Worth Fire Department (@FortWorthFire) September 11, 2018

Willie, a yellow Labrador, is about 2 1/2 years old. He was officially off-duty at the time he went missing, but the dogs — like all firefighters — are always on call, Drivdahl said.

Willie, who has been with the department for a few months and is one of three fire dogs, was with his handler at the time, Drivdahl said.