Updated

The Navy has explained how it spilled 94,000 gallons of jet fuel around Naval Air Station Oceana in Virginia Beach: Officials say a switch was left in the wrong position overnight.

Local news outlets report that officials say the fuel was mistakenly routed on May 10 into a 2,000-gallon tank, instead of a tank that can hold 880,000 gallons. The much smaller tank overflowed, and the spill wasn't discovered until the next morning.

The Navy said at a news conference Friday that they're still investigating how the switch ended up in the wrong position.

Officials say 25,000 gallons of the spilled fuel ran off the base and polluted waterways. An expected two-day cleanup has taken nine days and counting, with crews still working to contain the flow and absorb fuel.