The Mod Squad (1968)

S04E20 The Cave

Title: The Cave Plot: During a fierce sandstorm in the desert, Julie, Link, and Pete's vehicle fails, forcing them to take refuge in a deserted mine. Inside, they encounter a bitter old man, mourning the loss of his son in the war, who harbors a deep resentment towards hippies. In a fit of rage, he detonates explosives, sealing the three friends within the mine's dark confines.