The 1992 explosion in Guadalajara took place on April 22 in the downtown district of Analco. Numerous gasoline explosions in the sewer system during a period of four hours destroyed kilometers of streets; in particular, Gante street was the most damaged. April 22 is the 112th day of the year in the Gregorian calendar (113th in leap years). ...

The first cause of the disaster was a pipeline plated with zinc that was occluding in a humid environment with a steel gasoline pipeline. Both of them corroded, and gasoline leaked through the holes, right into the main sewer. General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. ... Gasoline is a petroleum-derived liquid mixture consisting primarily of hydrocarbons, used as fuel in internal combustion engines. ...

The second cause of the disaster was a U-shaped siphon in the sewer needed to duck under a recently built underground railway. The design allowed fluids to pass through, but also blocked the fumes. There should have been a siphon for the fumes passing over the underground railway. siphon principle A siphon is a continuous tube that allows liquid to drain from a reservoir through an intermediate point that is higher than the reservoir, the up-slope flow being driven only by hydrostatic pressure without any need for pumping. ... Sewers transport wastewater from buildings to treatment facilities. ...

Inhabitants were complaining for several days about a heavy gasoline smell, but despite the measurements and the imminent threat of explosion, the authorities refused to evacuate.

Officially 206 people were killed, nearly 500 injured and 15,000 were left homeless. The affected area can even be recognized by the more modern architecture, in sheer contrast with the surrounding area, with much older buildings.