By CBS3 Staff

PHILADELPHIA (CBS) — Multiple buildings in Center City, including CBS3, were evacuated after a strong smell of gas blanketed parts of Center City. Authorities are still trying to find the source of that smell.

City officials believed a tank being cleaned at the Philadelphia Energy Solutions refinery in South Philly caused the odor, but the Philadelphia Fire Department says they cannot confirm the initial report.

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The source of the smell remains undetermined.

The city says there is no health risk to the public.

The noxious odor swept across Center City around 10:45 a.m. Hordes of people filled the sidewalks as the workday grounded to a halt.

“We just got a text message that there was a gas smell in the building, and said wait for further instructions,” James Whitaker said. “We smelled it, alerted coworkers and gave them the option, stay or go outside.”

Fire radio was swamped with calls about odors resembling natural gas, or the additive mercaptan, a non-hazardous substance.

It was initially believed that the release of mercaptan while equipment was being cleaned at the refinery caused the odor. The fire department says a PES refinery fence monitor detected an unknown sulfur gas leaving the property around 8 a.m. Fire officials are still working to determine the cause.

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“So far, the fire department hasn’t located any source of these odors, or any hazardous conditions,” Philadelphia Fire Commissioner Adam Thiel said. “Despite some initial reports that perhaps some cleaning work they were doing on a tank down there was the source of the odors, we actually went in and checked that vessel – our Hazmat Task Force did – and did not find that to be the source of the odors.”


Thiel added that the calls to evacuate buildings was the right one.

“You smell something that smells like gas, call 911, that’s what we’re here for,” Thiel said.

There are still some aftershocks from this smell as parts of the Central Library are closed because of the odor. There were no illnesses or medical transports as a result of this mystery smell.

The refinery permanently shut down after a massive explosion and fire in June 2019. Investigators say the elbow valve ruptured, releasing flammable fluid containing hydrofluoric acid, an extremely dangerous industrial chemical. PES said the fire made it impossible for them to continue operations, forcing them to layoff more than 1,000 workers.

The 150-year-old site was the largest oil refinery on the East Coast and had been processing 335,000 barrels of crude oil daily into gasoline, jet fuel, propane, home heating oil and other products.

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CBS3’s Joe Holden contributed to this report.