SINGAPORE - Three men and a woman were injured after their car flipped over on the Ayer Rajah Expressway (AYE) on Sunday morning (July 15).
The police said they were alerted to the accident on the AYE towards Tuas near the Jurong Town Hall Road exit at about 7am.
The Singapore Civil Defence Force said that four people were taken to the National University Hospital.
The quartet, aged between 19 and 30, were conscious at the time, police said. Their injuries are believed to be minor.
The Straits Times understands that the car had skidded before it overturned. No other vehicles were involved.
The accident resulted in a traffic build-up on the expressway for about three hours, according to the Land Transport Authority (LTA).
LTA first tweeted about the accident at 7.30am, telling motorists to avoid the first and second lanes.
In a subsequent tweet, LTA said that there was a congestion till Clementi Avenue 6.
Police investigations are ongoing.