Power Outage Causes Gas Odor Across Delaware, Southern Pennsylvania

A strong odor described as sulfur- or gasoline-like was reported across New Castle County, Delaware, and Delaware County, Pennsylvania, on the morning of July 10, 2025, prompting numerous emergency calls. The source was traced to an equipment failure and power outage at the Monroe Energy refinery in Marcus Hook, Pennsylvania, which triggered an emergency shutdown and a visible flare burn-off. Officials stated that, despite the unpleasant smell, air quality monitoring showed no immediate health risks, though residents with respiratory issues were advised to stay indoors and turn off air conditioning as a precaution. Fire departments, particularly Talleyville in Delaware, responded to dozens of calls regarding the odor, and local agencies maintained communication with the refinery and environmental authorities. The situation stabilized as the flare ended, and the odor was expected to dissipate throughout the day. Monroe Energy has apologized for the concern and inconvenience caused to residents.