Join us for look into five engineering disasters... A dangerous cloud of gas explodes into Cleveland's worst fiery industrial disaster in 1944, killing 128 people. A dance competition turns deadly at the new Kansas City Hyatt in 1981, when a skywalk givesway and kills 114. In 1995, neighbors gaped at the spectacle of a $1.5-million San Francisco Bay area mansion breaking into bits as it fell into a massive sinkhole during a rainstorm. In 1931, one of the worst natural disasters ever occurred in the Yangtze River basin when six huge flood waves swept down the river destroying the insufficient dams and levees and killing at least 145,000 people. The miracle mineral that the U.S. was built upon turns out to be an invisible killer-an estimated 10,000 people die each year from asbestos-related diseases.