The Tacoa disaster (Spanish: tragedia de Tacoa) occurred on December 19, 1982 as a result of a fuel oil tank fire on the premises of the Ricardo Zuloaga thermal power plant, owned by Electricidad de Caracas and located in Tacoa, a seaside village and an area of Vargas, Venezuela.
There were 150 or more victims, amongst them many firemen, journalists and bystanders. All but two (who were killed in the initial tank explosion) fell as a result of a massive boilover from one of the affected tanks. It is the deadliest industrial accident ever occurred in Venezuela and the deadliest tank fire ever occurred worldwide.
The accident
At dawn, on Sunday, December 19, 1982, the sea-going tanker Murachi belonging to Maraven, a subsidiary of PDVSA, was moored off the Ricardo Zuloaga power plant in Tacoa and about to unload 15,000 tons of fuel oil, which would be used as fuel for power production. Two plant operators climbed atop tank no.8, a 55 m diameter, 17 m high cylindrical atmospheric tank located on a hill, which was scheduled to receive the fuel, for routine checks in preparation for the operation, including a reading of the level in the tank. When they opened the gauging hatch, hot hydrocarbon vapors interspersed with the air creating an explosive mixture. A massive explosion ripped off the tank's conical roof and killed the two operators carrying out the checks. A tank fire started, which extended to secondary fires in the containment bunding.
It is unclear what the source of ignition might have been, although it is speculated that it could be a non-intrinsically safe lamp or even a match used to illuminate the level dip tube. The liquid stored in the tank (no.6 fuel oil, also known as residual fuel oil or bunker C) is non-flammable, as its flash point is 71°C, well above ambient temperature. However, in the conditions in which it was stored on that day, it became flammable, although the mechanism by which this occurred is not fully confirmed. The tank was heated by several steam coils in order to keep the highly viscous fluid in pumpable conditions. On the night of December 18, a high-temperature alarm for tank no.8 had gone off, indicating excessive heating. One of the steam coils was isolated in response. Apart from the contribution of the higher temperature, it is possible that inappropriate blending of the fuel oil was responsible for the presence of lighter components with low flash point.
It soon became clear that Electricidad de Caracas had no contingency plans for a fire in their fuel oil storage tanks. The company lacked a fire brigade, and their staff had no training or instruction. The emergency response was delayed by more than 20 minutes as the first fire engines navigated tortuous roads to reach the remote site. Firefighting apparatus and personnel arrived from across the region over the next few hours, including firemen from the port of La Guaira and the nearby Simón Bolívar International Airport in Maiquetía. Most of the equipment was however unable to access the elevated fire site. Under any circumstances, extinguishing an open tank fire of that size would have been extremely difficult; lack of water and foam made this task impossible. The order was given to let the tank burn itself out. However, given the intensity of the fire, action was still required to prevent spread to the neighboring dikes. During the morning, more than 100 firefighters were employed, later joined by more intervention personnel from other entities, including the Guardia Nacional, Metropolitan Police, and PDVSA technicians among others. Media personnel, including from Venezolana de Televisión and El Universal newspaper, arrived at the site to provide news coverage.