Sitting atop a small hill in Punggol was a lone tree that graced many an Instagram photo, often silhouetted against the backdrop of a pastel- hued dawn or flaming sunset.

Yesterday, a small crowd gathered at Punggol Waterway Park to bid goodbye to the popular tree, dubbed the "Punggol Lone Tree", or Instagram tree.

Before noon, a group of workers cordoned off the area near the tree as they prepared to cut it down. They started removing the branches at about 12.30pm. Within 15 minutes, the tree was gone.

Sales assistant Tan Siew Kheng, 58, was among those who headed down to Punggol to catch a last glimpse of the tree.

"I feel quite pained to see the tree being cut down - it is a waste as it makes (this) such a picturesque spot. But at least I have taken a video of it as a souvenir," she said.

Citing public safety concerns, the Housing Board said last Wednesday that the tree had to be removed as parts of it had been falling off without warning.

The tree, which belongs to the fast-growing Albizia species originating from eastern Indonesia, was struck by lightning in July and lost half of its branches.

HDB said arborists had checked the tree earlier this month and certified that it was dead.

More than 1,744 posts have been tagged #instagramtree on Instagram, with most of them showing the Punggol tree. The tree is so famous that it even shows up on Google Maps as "Punggol Lone Tree".

Another tree located next to the Punggol Lone Tree has been cheekily geo-tagged by a few online users as "The Tree That Tried".

Mr Kavickumar Muruganathan, head of eco-certifications and lead environmental engineer at the Singapore Environment Council, backed the authorities' decision to fell the tree.

"Falling branches may pose a risk of injury. It is also important to note that the tree belongs to a fast-growing species and is not at risk of extinction," he said.