A routine trip to Costco turned chaotic for thousands in Concord's East Bay as a refrigerant leak prompted an evacuation of the wholesale giant, authorities said. Approximately 1,000 people, including customers and employees, were hustled out of the store on Monument Boulevard after a white cloud of potentially hazardous gas sent a wave of alarm on Wednesday afternoon.

According to KRON4, the Contra Costa County Fire Department responded to the call at 2:06 p.m., when employees and patrons noticed the ominous vapor. The incident led to an almost cinematic exodus of some 800 shoppers and 200 staffers from the premises, though thankfully, no injuries were reported.

Following the evacuation, images emerged showing a Hazmat truck and a medic on standby outside the large warehouse retailer, underscoring the gravity of the situation. "Con Fire said a medic was present as well in case anybody complains of injuries," reported KRON4, highlighting the swift response to the potential threat.

The Contra Costa Fire Department's Public Information Officer relayed via their X post that the Hazmat Team and firefighters had been deployed to facilitate the safe exit of all inside. The store was subsequently cleared for re-entry after the fire department had deemed it safe, "Update: firefighters have cleared the scene and the store is reopen for business," the Con Fire PIO broadcasted.

Costco on Monument in Concord has been evacuated from a refrigerant leak. #ConFire Hazmat Team and firefighters on-scene to assist in evacuating approximately 800 customers and 200 employees; no injuries reported at this time. pic.twitter.com/TBrTRcetet

— Con Fire PIO (@ContraCostaFire) April 26, 2024

The substance used in cooling systems can pose mild to severe health risks upon exposure, though specifics on how the leak occurred are yet to be provided.