1.57. A man opens his mouth and dies shortly afterwards.
1.57 answer: He annoyed the mafia several hours ago; he's now underwater and wearing cement Reeboks. ("Style is everything, and cement Reeboks sure are stylish.") (RA)
1.57 variant answer: The man is a vampire, about to bite a girl. Her boyfriend arrives, realizes what is happening, and kills the vampire by driving a wooden stick through his heart. (This was the original answer, by Kari Hautamaki. But this answer would move the question to section 2, and I like Russell's answer better anyway.)
1.57 variant answer: The man opens his mouth; some killer bees (which tend to prefer attacking darker areas) fly inside and sting him; the swelling of his throat asphyxiates him. (MI)