A large portion of the cliff face at the Singapore Quarry recently broke off, and the National Parks Board (NParks) is monitoring the situation.

Large chunk broke off

Adrian Kuah, a hiker, was witness to the geological phenomenon.

In a Facebook post on July 11, Kuah said that he and several other park-goers were standing on the wooden observation deck opposite the quarry when they heard a sudden "rumbling, tearing" sound.

The incident happened without warning, and "with shocking quickness", a slab of the cliff broke off and crashed into the water below.

Kuah shared a photo of the aftermath, pointing out the lighter orange portion of the cliff, which was where the rock had sheared off.

He added that he estimated the broken chunk to be the size of a minibus.

The incident occurred so quickly that none of the visitors had time to take a video, Kuah said, despite them whipping out their phones as fast as they could.

"Funnily enough, some folks continued to stand there with their phones pointed at the spot, as though expecting a replay," Kuah quipped.

Could be due to recent heavy rain

In response to Mothership's queries, NParks' Group Director of Conservation Lim Liang Jim said that they are in the midst of assessing the condition of the cliff.

This rockslide incident, he explained, could have been caused by overburdened soil at that section of the cliff and the continuous rain over the past few days.

Lim said that their preliminary assessments do not show any signs of further soil movement. In the meantime, NParks will continue to monitor the stability of the cliff.

Access to the viewing platform at the Singapore Quarry still remains open, as the cliff is not linked to the viewing deck.

Top photo from Adrian Kuah / FB and Nicholas Choo / Google Maps