Students at Marshall High School were evacuated this morning after a strong smell of Chlorine was detected.   The Marshall Fire Department was called about 10:30am, and moved the students out to a safe distance, upwind from the chemical smell.  Public Safety Director Jim Schwartz says the students were moved to the nearby football field, and then bussed to the middle school.   He says one school maintenance worker having breathing difficulties was treated at Oaklawn Hospital.    Schwartz says the fire department found a bucket of chlorine near the pool area that was the source of the chemical smell.   Schwartz says the evacuation plan went off without a hitch.  He says environmental crews are working to ventilate the smell, and says they expect school to re-open on Wednesday, but says that isn’t a sure thing yet.