In working to extinguish a fire, crews must be careful to not dump too much water too quickly in a move that could tip or capsize the roof, exposing more of the oil to the flame.
Most of the fires are small and extinguished relatively quickly.
Newer tanks have sprayers built into the top that can quickly pour foam and water inside.
With older tanks, crews must carry large fire hoses up the steps along the outside of the tank wall. Once they reach the top, they use long wands to cover an area with foam to create a safe space to operate while the crews work to put out the rest of the fire.
But if a tank were fully engulfed, those routine practices would not be enough.
A lightning strike in 2006 created such a fire in Glenpool.
Most of Cushing's newer storage tanks are built with enough space between them that fire is unlikely to spread. Many of the older tanks, however, are so close together that if one caught fire, crews likely would use the high-capacity water cannons to coat the walls of nearby tanks in an attempt to keep the fire from spreading.