The Guadalajara Sewer Explosion
April 22, 1992 - At 10:00 in the morning, residents of Guadalajara, Mexico noticed a manhole cover was bouncing up and down as white smoke puffed out of the sewer. Minutes later, the first of many explosions would rip the streets apart. When it was all over, 252 people were dead, 500 were injured and over 15,000 were left homeless.
The disaster was mainly caused by a leaking Pemex gas line that dumped gasoline into the sewer system. People had been complaining for several days about the smell of fumes, but city officials did not think it was a dangerous situation.
Four officials with Pemex, Mexico's state-owned petroleum company, were indicted and charged with negligence, but in the end everybody was cleared of any wrongdoing.