A truck was found stuck at the entrance of an underpass at Marina Bay yesterday morning.
Photographs circulating on Facebook and Instagram showed it was vertically wedged between the road surface and the ceiling of the tunnel, blocking almost half of the tunnel's entrance.
The truck's cabin was nearly separated from its trailer.
No one was injured in the accident, but it was unclear how it happened.
The Land Transport Authority (LTA) said an over-height vehicle had hit the underpass along Marina Station Road towards Central Boulevard.
The underpass was temporarily closed to traffic to facilitate repair works and checks.
An LTA spokesman added that they were alerted to the incident at about 9am. The underpass was reopened to traffic at about 12.40pm after it was certified safe for motorists.
A 35-year-old communications executive, who wanted to be known only as Mr Teo, said he was at the area at about 9am and had heard from a fellow passer-by that the truck was carrying a crane and had hit the top of the tunnel.
This may have caused the vehicle to flip up.
"I didn't see anyone injured, just a few people sitting by the kerb. I also saw policemen diverting traffic away from the area," he said.
Police said they received a call yesterday morning at about 6.05am requesting assistance at the location.
Investigations are ongoing.