An explosion occurred around 10 am in the sewer line of Mexico’s second largest city amidst a metropolitan area; this blast was followed by a series of explosions between 10:30 and 11:30 am. Then very early the next morning, two more blasts were set off, one of which in an industrial district.
These explosions resulted from the ignition of gas accumulated in the 3.50-m diameter sewer collector pipes, buried 8 m below the pavement, subsequent to a hydrocarbon pipeline leak.
The toll was devastating: 206 deaths, 500 disappeared, 1,800 injured and 4,500 displaced; 13 km of streets obliterated, some hollowed out by ditches several metres deep. Water, electricity and communications networks were all perturbed; 1,500 houses were destroyed. The cost of external damage was estimated at 396 million francs.