Smitty and Billy were impersonating armored car drivers to steal the money from the bank, pretending the "regular guy" was "on vacation." When the real armored car drivers came, Smitty and Billy shot one of them, and then Riggs went after them. Smitty was fighting Riggs in Billy's car. During the fight, Riggs manages to grab Smitty and throws him out onto the sidewalk, to which Smitty manages to escape, with Billy being arrested.
The next day at the MESA construction housing development site, Jack Travis has a word with Smitty telling him he doesn't like it when his men fail, but acts like he doesn't care by shaking Smitty's hand and say they'd start fresh, and then Hatchett knocks Smitty out and pushes him into the pouring concrete. Travis' other henchmen bury him in it, killing him.