BOISE, Idaho — A 5-year-old boy who went missing after wandering away from his own birthday party is believed to have been found dead, Idaho police said Tuesday.

Matthew Glynn was last seen at home late Monday afternoon while celebrating his fifth birthday with friends and family, Boise police said.

Following a massive search, search crews found a body in a canal on Tuesday, Boise police said. The Ada County Coroner’s Office will make an official identification, though the victim is believed to be Matthew, police said.

The body was found in a canal about a half-mile north of where the boy went missing, police said. There appears to be no signs of foul play, police said.

“We are heartbroken over this development today,” Boise Police Chief Ron Winegar said in a statement. “We want to thank our many partners for their response as well as the public for their willingness to help another member of our community in a time of need.”

Officers had responded to a report of the missing child shortly before 6 p.m. local time, Winegar said. Matthew, who was nonverbal and had autism, was wearing Batman pajamas when he went missing, Winegar said.

Authorities immediately launched a large-scale search involving drones, ATVs, UTVs and tracking dogs that primarily focused on waterways in the area, as Matthew was drawn to water, the police chief said.

Police also conducted door-to-door searches to check people’s backyards, Winegar said.

Ron Christensen with Idaho Mountain Search and Rescue said 30 personnel were also involved in the search Monday night, including mountain bike teams that covered parts of a local greenbelt.

The group deployed UTVs with flashing lights and played the song “Wheels on the Bus” through speakers to try to attract Matthew, Christensen said.

The Boise Fire Department was also involved in the search.

“Sadly, this is not the outcome we were all hoping for. Our hearts go out to Matthew’s family, and we extend our deepest condolences during this incredibly difficult time,” Boise Fire Chief Mark Niemeyer said in a statement.