life-threatening injuries. a man believed to be intoxicated is in custody this morning as police try to piece together just how this happened. five alarm be advised a multiple casualty incident. reporter: a party atmosphere quickly turned to a scene of destruction and despair. i saw a dark truck run down a white car off the road, swerved, lose control and just run into the people. reporter: at least 21 people were hospitalized after the crash, including young children as well as a new orleans police officer. a reporter for fox station wvue recorded this video and identified the man in custody as the driver of the pickup. put him in the car! this is the driver! reporter: the same man seen in this photo from the new orleans advocate. we believe the suspect was highly intoxicated. he is in custody. he is being investigated right now. reporter: thousands of people were attending and participating