POCATELLO, Idaho -

A 23-year-old Garden City, Kan., man was flown to a Salt Lake City hospital Saturday after he was injured while working at the Simplot Don plant near Pocatello. The Power County Sheriff's Office said on Monday that Derrick E. Martinez may have been exposed to ammonia.

Martinez was found unconscious in a mobile testing trailer around 12:40 p.m. Saturday. He worked for a Simplot subcontractor called Blick's.

The sheriff's office said Martinez was listed in critical condition Monday.

Investigation of the accident is continuing.