The United States post office on County Line Road in Columbus was closed for hours today after a Hazmat unit responded to a suspicious package at the facility which turned out to be rotten seafood, officials said.

The post office, 9232 County Line Road, and a portion of the road was closed about 10:40 a.m. after 911 was called about a cardboard box leaking an unknown substance in an employee-only part of the office, said Fire Marshal Ricky Shores.

“There was a report of an employee having a respiratory complaint in relation to the package,” Shores added.

Firefighters responded to the post office, closed the road and got the post office employees out of the building. The Hazardous Materials Unit then arrived and sent in a robot with equipment to monitor the air, Shores said.

“We had absolutely no elevated readings,” the fire marshal added. “The air was not contaminated.”

The post office employee who had breathing problems was decontaminated as two men donned Hazmat suits and entered the building. Based on the information from the robot and on what the men saw, they opened the cardboard box, Shores said.

“They determined that it was rotten seafood,” he added. “The employee’s doing fine right now.”