When a breaker at the Ives Dairy Substation in Miami, Fla., tripped open due to a surge in early 2001, it malfunctioned and created an arc fault (a co" />
When a breaker at the Ives Dairy Substation in Miami, Fla., tripped open due to a surge in early 2001, it malfunctioned and created an arc fault (a continuous lightning bolt that acted like an uncontrollable welding torch) between the hot lead and wherever it could find a ground, thus pulling far more current then the facility was designed for.
This caused the coolant (mineral oil) inside the primary transformer to overheat to critical levels until it was boiling in a highly flammable state. This boiling caused pressure to rise inside the transformer (like a pressure cooker) until the seals finally blew. Mineral oil vapor proceeded to pour out at that point (the plume of white fog at the end), which ignited on the arc fault. The flames caused by this immediately ignited back to the source (the boiling transformer tank), which ignited the mother load of oil inside causing the substation to explode in a giant ball of fire.
The sudden loss of all transformer coolant resulted in a simultaneous flash-meltdown of the transformers innards, which immediately caused the main high-voltage fuse to blow (the loud explosion at the end), finally killing the arc.
Access this 37-second video by clicking on the link below.