Officials said the leak happened during construction at the Family Fare BP on Martin Luther King Jr. Boulevard.
On Saturday, Robert and Sheile Amareld found the dead fish beside the Crow Branch Creek near their home. Now the residents are concerned their water may be contaminated.
"We found some dead fish down there and it was kind of concerning. We collected them so the animals wouldn't eat them, and we gathered some water and we found it was a little darker than the other stream that wasn't affected," Robert Amareld said. "We could smell some gas, only when you got real close to the water."
Residents said they also started to notice a foam starting to gather in the creek that they had never noticed before.
On Friday, authorities said they did not know sure how much gasoline got into the creek. They were doing testing and trying to trap any gasoline they found.
For that, the neighborhood's association president, Julie McClintock said she is grateful and praised the town for their response. However, she said she and others still have concerns.
"Has all the gasoline and ethanol been trapped? Another concern would be, are we doing everything we can to prevent this kind of thing from happening again?" McClintock said.
ABC11 reached out to the state's Division of Environmental and Natural Resources, but was unable to reach anyone.