Crews are still working to clean up thousands of gallons of jet fuel in Virginia Beach, and the U.S. Navy now says they know why the spill occurred.
Officials said Friday that a switch was left in the wrong position when the spill occurred May 10.
The 94,000 gallons of jet fuel was mistakenly routed into a 2,000-gallon tank at Naval Air Station Oceana, local news outlets report. It should have been routed into a 880,000-gallon tank instead.
The much smaller tank overflowed, and the spill was not 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.
The Navy moved 177 people who live nearby into a hotel, The Virginian-Pilot reported. Several people reported having headaches and sore throats.
An expected two-day cleanup has taken nine days and counting, with crews still working to contain the flow and absorb fuel.