FORT JENNINGS, Oh. (WOWO): Putnam County Sheriff’s Officers along with several fire departments were joined by nearly 1,000 volunteers to search for a missing 5 year old boy.

Issac Schroeder went missing around 3 o clock Wednesday afternoon from his home near Fort Jennings. Isaac is autistic, adding to the danger according to authorities who say he is also non-verbal and could not respond if someone calls his name. Isaac was last seen wearing only underwear with Thomas the Train on them.

As of Thursday afternoon, officials had searched the equivalent of 1200 miles along the Auglaize River, near his home and found nothing. Authorities say there is no evidence that leads them to the river, other than proximity and no evidence pointing to an abduction.

Officials have been joined by the FBI and the Ohio Bureau of Criminal Investigation in the search.