Watch Modern Marvels Season 6 Episode 21 Online

Throughout history, the builders and engineers who paved our way out of the caves and into the modern world have also caused some of our worst disasters. What happens when their calculations prove wrong and it all comes tumbling down? From Hammurabi’s days, when the first building laws were instituted, to today’s potential nuclear or chemical disasters that can spell death for thousands, we’ll take a harrowing 2-hour tour through some of history’s greatest engineering mistakes.