The carrier said in a statement that the nose gear of an Airbus A330-300 "retracted while the aircraft was undergoing a landing gear system check."
"There were no passengers or crew on board at the time. One engineer who was on the aircraft was not injured. Singapore Airlines will be cooperating fully with the authorities in their investigations," the statement said.
It said the damage to the plane would be assessed after it is removed from the gate.
The plane had been due to serve flight SQ890, scheduled to depart for Hong Kong from Singapore's Changi Airport at 7:35 a.m. It had arrived from Shanghai's Pudong International Airport in the wee hours of the morning.
Another plane was used for the flight to Hong Kong, taking off more than 40 minutes after the scheduled departure time.
The collapsed plane had been in service for more than six years, according to records. Its maiden flight was in April 2009.
On May 23, another Singapore Airlines Airbus A330-300 temporarily lost power in both engines on a flight from Singapore to Shanghai carrying 194 people, causing it to descend 13,000 feet (4 kilometers) before normal operation was restored.