(HOUSTON) -- Nearly 20 people were hospitalized on Friday night after falling sick during a high school football game at Barnett Stadium in Houston.
The 22 students fell ill during the second half of the game between Yates and Austin High in which Yates won 47 - 14. The students, mostly members of Austin's marching band, had symptoms of nausea and vomiting after being exposed to an unknown substance. All were transported to five local hospitals for treatment.
The Houston Fire Department was at the scene and say hazmat teams found no chemical substances that would account for the illness.
Officials are investigating and interviewing the patients.
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