A hall at Marina Bay Sands (MBS) exhibition centre partially flooded around noon on Tuesday.
Exhibitors for Singapore International Water Week were at the area.
An MBS spokesperson on Tuesday said, "At approximately 12:05pm today, a small area of Hall F was affected by an overflow of rainwater. Our teams promptly provided assistance to the event organizer and any affected exhibitors."
She said the area was cordoned off and cleaning completed.
MBS suspects the source of the overflow "is a drainage issue due to heavy rains in the morning".
She said investigations into the incident are being made to prevent a similar occurrence in the future.
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