The Atomic City

The Atomic City is a 1952 drama film directed by Jerry Hopper, starring Gene Barry and Lydia Clarke.

Frank and Martha Addison live in Los Alamos, where he does topsecret work as a physicist. They have a young son, Tommy, who goes with school mates to Santa Fe for a carnival, where teacher Ellen Haskell cant find him when Tommys winning ticket in a raffle is announced.The Addisons receive a telegram telling them Tommy has been kidnapped. The teacher also gets in touch about their boy being missing, but Frank, ordered to keep quiet, lies that he left work early and picked up his son. ........

Source: Wikipedia