The Andromeda Strain

After an errant satellite crashes to earth near a remote New Mexico village, the recovery team discovers that almost everyone in town are victims of a horrible death caused by an unknown biological agent, with the mysterious exception of an infant and an old homeless man. The survivors are brought to a state-of-the-art laboratory descending five stories beneath the ground where a group of puzzled scientists race against time to determine the nature of the deadly microbe before it wreaks worldwide havoc.