1992 Guadalajara Explosions - Investigation

Investigation

An investigation into the disaster found that there were two precipitating causes:

• New water pipes, made of zinc-coated iron, were built too close to an existing steel gasoline pipeline. The underground humidity caused these materials to create an electrolytic reaction, akin to that which occurs inside a Zinc-carbon battery, as the reaction proceeded it eventually caused the steel gasoline pipe to corrode, creating a hole in the pipeline that permitted gasoline to leak into the ground and into the main sewer pipe.

• The sewer pipe had been recently rebuilt into a U-shape so that the city could expand their underground metro railway system. Usually sewers are built in a slope so that gravity helps move waste along. In order to get the U-shape to work, an inverted siphon was placed so that fluids could be pushed against gravity. The design was flawed, however. While liquids were successfully pumped through, gases were not, and gasoline fumes would build up.