"I had a seat in the back. I was sitting there. I was talking to the lady next to me. We heard a little bit of commotion. I looked up and saw a guy coming onto the plane wearing a full gas mask, which was kind of odd. He didn't have a filter, which I thought was more strange," Joseph Say told KTRK.
After the person was escorted of the plane, the flight continued on to Houston according to KPRC-TV.