Passengers were informed that four crew members had to be on that flight in order for them to make it to work in the morning, so four volunteers were needed to deplane. They'd be given hotel accommodations & another flight the next afternoon. Well no one volunteered so the airline picked four people. 3 went willingly. One man did not. Reportedly, he claimed to be a doctor & said he had patients to see in the morning. So Chicago airport police were called & the passenger was dragged off the plane! Somehow he came running back on the plane & was subsequently removed again but this time on a stretcher. Either they wanted to restrain him or he was in need of medical attention.... or both.