Tang Plaza's basement food market had to be evacuated yesterday when a pipe burst, sending the smell of human waste through the underpass.
One commuter said she could smell the stench all the way from the station control at Orchard MRT.
About 20 people had to be evacuated after the pipe burst at around 2pm near Tang Marketplace, said a mall spokesman.
The Orchard MRT underpass exit to Scotts Road, and all other routes to the basement from the ground floor had to be cordoned off.
Dense crowds formed when shoppers were diverted to the only other exit outside the front entrance of Tangs department store.
Engineers and sewage trucks were deployed to repair the pipes, and a Tangs spokesman said an overnight operation had also been launched to clean up the basement.
At around 4pm, guests that The Straits Times spoke to at the Marriott Hotel said they could still smell the stench.
On September 5, a section of stores at Ion Orchard shopping mall was closed off due to a waste-water leak.
Stores affected included luxury brands Louis Vuitton and Dior.