Police are investigating after thieves stole hundreds of gallons of fuel from a Detriot gas station last month.

Despite several working security cameras, two men used a device to hack a gas pump and steal 600 gallons of fuel at Marathon gas station about 1 p.m. on June 23, Click Detriot reports. The device the men used in the heist made it so the gas station clerk could not control the pump.

However, the clerk wasn’t aware of the situation until it was too late.

Gas was free for an hour and a half and ten vehicles filled up during that time. About $1,800 worth of gas was stolen, but it was not known if the drivers who filled up their tanks with the gas were working with the thieves.

"I can't even imagine how they could pull that off without the gas people inside knowing," one gas station customer told WJBK. "Couldn't they shut the pumps off?"

Gas station worker Aziz Awadh told the news station that the system wouldn’t acknowledge his commands and that he had to use an emergency kit to shut down the gas pumps. He called authorities shortly after.

"I tried to stop it but it didn't work," Awadh said. "I tried to stop it here from the screen but the screen's not working. I tried to stop it from the system; nothing working [sic]."

Although police discovered that the suspects used a device to hack the gas station, it was unclear precisely what that device was. 

Photos of the suspects are available here

gas station Police in Detroit are investigating how thieves stole hundreds of gallons of fuel from a gas pump last month. A gas station is pictured on June 1, 2018 in New York. Photo: Don Emmert/Getty Images