The Wrecker.

The Wrecker is a flinty-eyed demolition engineer named Regan (Jack Holt). While he's off on another assignment, Regan's wife Mary (Genevieve Tobin) and supposed best friend Cummings (Sidney Blackmer) engage in some heavy petting. About to wash his hands of his faithless wife and his back-stabbing chum, our hero is compelled to save both their lives when they're pinned under the wreckage of a collapsed schoolhouse. George E. Stones supplies some good-natured ethnic humor as Regan's junk-dealer pal Shapiro.