San Juanico disaster: A series of explosions at the Pemex petroleum storage facility at San Juan Ixhuatepec in Mexico City starts a major fire and kills about 500 people.

The San Juanico disaster involved a series of fires and explosions at a liquefied petroleum gas (LPG) tank farm in the settlement of San Juan Ixhuatepec, a municipality of Tlalnepantla de Baz, State of Mexico, Mexico, on 19 November 1984. The facility and the settlement, part of Greater Mexico City, were devastated, with 500–600 victims killed, and 5000–7000 suffering severe burns. It is one of the deadliest industrial disasters in world history, and the deadliest industrial accident involving fires and/or explosions from hazardous materials in a process or storage plant since the Oppau explosion in 1921.

Pemex is the Mexican state-owned petroleum corporation managed and operated by the Mexican government. It was formed in 1938 by nationalization and expropriation of all private oil companies in Mexico at the time of its formation. Pemex had total assets worth $101.8 billion in December 2019 and as of 2009 was Latin America's second largest enterprise by annual revenue, surpassed only by Petrobras. The company is the seventh most polluting in the world according to The Guardian.

Petroleum, also known as crude oil or simply oil, is a naturally occurring, yellowish-black liquid chemical mixture found in geological formations, consisting mainly of hydrocarbons. The term petroleum refers both to naturally occurring unprocessed crude oil, as well as to petroleum products that consist of refined crude oil.