Tunnel collapse nearly led to Mexico City drain explosion

MEXICO CITY (AP) — Mexican authorities said the collapse of a clandestine tunnel dug to steal gasoline from a government pipeline probably triggered a chain of events that nearly blew up one of the few outlets for moving water out of the closed and flood-prone Mexico City valley.

The near-miss occurred in late March, when operators at a pumping plant reported gas fumes. Fumes at explosive levels were also detected in one of the city's few massive drain outlets, but full details were not revealed until Friday.

An inspection found that a gasoline pipeline that runs along the northern edge of the city had been riddled with at least eight illegal taps. The thieves had apparently left some of their taps open, allowing gasoline to soak into storm drains, said Javier González, the head of logistics for the state-owned Pemex oil company.

He said the sophisticated theft scheme — which apparently had operated for years — included digging underground tunnels that led from the pipelines to private properties, where rubber hoses led from the taps to staging areas where huge tanks were filled with stolen gasoline.

The tunnels had fans and were shored up with wooden boards and planks. But authorities found that one such tunnel within the city limits had partly collapsed,

“There was apparently an inward collapse in the tunnel, which led these people to get out quickly, leaving the clandestine tap open,” González said.

Soldiers and investigators found a total of four tunnels, as well as warehouses and lots with hundreds of large tanks used to store fuel.

Mexico City has no natural water outlet and relies on pumping plants to move rain and drain water up a slope and out of the valley to surrounding agricultural areas that use it to water crops.

The pumping plant in the suburb of Ecatepec was closed temporarily but reopened after the fumes dispersed. Had the leak occurred during Mexico’s rainy season, which starts in June, the results could have been catastrophic; The city has a centuries-long history of floods.

While the government had declared victory in the fight against fuel theft from its pipelines in 2019, the army found 3,780 illegal pipeline taps between Sept. 1, 2019, and June 30, 2020.

According to an official report, in March Mexico continued to lose an average of about 4,000 barrels of gasoline and diesel every day to fuel theft, but President Andrés Manuel López Obrador said massive fuel thefts supported by residents of entire towns now happen “in very few” cases.

“Let's hope that doesn't come back," the president said Friday, “but there continue to be clandestine taps.”

On Jan. 18, 2019, an explosion at an illegally tapped pipeline further north of Mexico City killed at least 134 people. The explosion occurred in the town of Tlahuelilpan as residents collected gasoline leaking into a ditch from the illegal tap.