The antagonist Meyer dies of a heart attack. In real life Henry Beckman who plays him ultimately succumbed to a fatal heart attack, although it was more than 30 years later and he had achieved a great age.
Very similar plot to the British thriller movie Juggernaut (1974), which starred Richard Harris, Anthony Hopkins and Omar Sharif and was released the previous year. As well as the bomber being a disaffected government worker motivated by revenge, and the "cut the blue or the yellow" tense climax, a key detail in both stories is that the bombs are concealed inside oil drums.