X: The Unknown (1956) Subtitles

When a fissure explosively opens in an English mud flat during a military exercise there, injuring one soldier and killing another, an American research scientist at a nearby nuclear plant joins with a British investigator to discover why the victims were radioactively burned and why, shortly thereafter, a series of radiation-related incidents are occurring in an ever-growing straight line away from the fissure.

IMDb: tt0049967 · TMDB: 26865