(Reuters) - An explosion killed at least 26 people and halted operations at Venezuela's biggest oil refinery on Saturday in the country's worst industrial accident in recent memory.
Experts say mismanagement, electrical faults and lack of maintenance have been the most frequent causes. Following is a list of major PDVSA accidents and incidents since 2002:
* At least 26 people were killed and more than 50 wounded when an explosion caused by a gas leak tore through storage tanks at the giant 645,000-barrel-per-day Amuay refinery.
* An explosion at a drill site in the western state of Zulia killed one worker and wounded three others.
* A tanker operated by PDVSA damaged its hull by hitting a sandbank in the Caribbean. No one was hurt.
* A fire temporarily halted production at Venezuela's second-biggest refinery, the 310,000-bpd Cardon facility, which is near Amuay.
* A small fire briefly stopped a distillation unit at Amuay.
* A tanker collided with a loading dock at Petroanzoategui, one of Venezuela's heavy crude upgrader.
* A small explosion stopped a unit at Petropiar, another heavy oil upgrader.
* A fire briefly halted operations at a terminal that serves Petroanzoategui, Petropiar and a third upgrader, Petromonagas.
* An explosion at Petrocedeno, Venezuela's fourth upgrader, killed one worker and wounded three.
* Three fires broke out at oil storage terminals on Bonaire and Curacao islands, and at a loading dock at the Cardon refinery on the mainland. The two terminal fires were believed to have been caused by lightning storms.
* An explosion forced the shutdown of the alkylation unit at the Puerto La Cruz refinery. There are no casualties.
* Several oil spills marred Lake Maracaibo, Venezuela's oldest oil exploration area. PDVSA blamed thieves who it accused of sabotaging facilities to steal equipment.
* The Aban Pearl, a natural gas exploration rig, sank in the Caribbean sea. All 95 workers were rescued safely.
* At least two barges operating on Lake Maracaibo sank while carrying out maintenance work on wells. There were no casualties.
* A worker was killed and buried while operating a coke transporter at the Jose solids terminal in the eastern state of Anzoategui.
* A worker at the Petroboscan joint venture, formed between PDVSA and Chevron, died of a head injury while operating a drilling rig in Zulia state.
* A dozen failures at refineries were recorded, including the spillage of 140,000 gallons of gasoline at Curacao's giant Isla refinery, run by PDVSA. That led to the evacuation of schools and businesses in the area.
* There were five accidents that claimed three lives and injured five people at the Paraguana Refining Complex (CRP) -- one of the biggest in the world with the capacity to process 955,000 barrels per day (bpd).
* Five workers died and 20 were wounded in an explosion during November at the CRP.
* After six incidents at the complex in a year, the CRP manager admitted that the frequency of fires, explosions, leaks, and leaks of oil had almost doubled compared to 2004, and that the incidents had increased in severity.
* A report said PDVSA would need to spend about $500 million to clean up the company's environmental liabilities, including abandoned hazardous waste.
* A huge fire killed at least two workers at the La Salina boarding terminal in Zulia state. Several others died from their injuries in the following months.
* An explosion at an electrical substation at the 640,000 bpd Amuay refinery, Venezuela's largest, injured two workers.
* Two drilling barges caught fire and sank in Lake Maracaibo.
(Reporting by Marianna Parraga, Daniel Wallis and Brian Ellsworth)