An unexpected roadblock left about a dozen drivers turning to each other for help.
They each fueled up at a Fort Washington Mobil gas station on Livingston Road off Indian Head Highway.
Minutes later, their cars stopped running.
After Tony Powell had problems with his truck, a tow truck driver told him that he saw a trend.
"He asked me 'did you stop and get gas down the street...over across the street.' I said 'yes.' He said 'well you got 10 other cars with the same problem who just came out of that gas station."
The station's general manager spoke with me on the phone.
Andre LeBlanc works for Petroleum Marketing Group, which owns, operates or supplies gas to more than 350 stations. He says the tank the fuel came from had been tested for water contamination when it was last filled Monday morning and there was not a problem.
But sometime after the last test, a ventilation pipe connected to the underground tank cracked when the concrete shifted.
LeBlanc says this is extremely rare and as soon the problem was detected the station shut down.
About 8 inches of rainwater had drained into the tank, contaminating the gas.
The gas station is asking anyone who stopped there Monday between 5:30 a.m. to 4:30 p.m. and had car troubles to fill out an incident report.
You can do so in person at the station - 11800 Livingston Road, Fort Washington - or by calling the Petroleum Marketing Group at (703) 494-5800.
LeBlanc said if your car is looked at by your insurance company or a reputable mechanic and was damaged by contaminated gas from his station, the station will cover the repair costs.
Contractors have been on site since Monday afternoon, clearing out the contaminated gas, cleaning tanks and lines, and putting in a new ventilation tube.
The Maryland Department of the Environment was also called in.
The gas station is continuing repairs and testing with the goal of opening safely, once the work is completed.