Residents along Tampines Street 12 heard an argument go on for five minutes before they saw a teen crashing through a walkway shelter.
The 18-year-old had fallen from the sixth storey of the block on Sunday morning (Dec 27), Shin Min Daily News reported.
An ambulance and the police were immediately called. According to an eyewitness, the injured teen could still nod as the paramedics examined him.
The police told AsiaOne he was conveyed conscious to Changi General Hospital.
Photos showed a large hole in the walkway shelter from where the teen had fallen through, as well as rubble that was scattered around the area.
The teen is believed to have jumped after his girlfriend broke up with him.
With the company of his friends, he visited the block to speak with his girlfriend.
One of them told the Chinese daily that the teen's girlfriend had asked for a breakup but he refused.
"They then went to the staircase landing at level six to talk, that's when this tragedy happened."
A pair of black shoes and a paper bag remained at the staircase landing.
Police investigations are ongoing.
SINGAPORE HELPLINES
- Samaritans of Singapore: 1800-221-4444
- Singapore Association for Mental Health: 1800-283-7019
- Care Corner Counselling Centre (Mandarin): 1800-353-5800
- Institute of Mental Health's Mental Health Helpline: 6389-2222
- Silver Ribbon: 6386-1928
rainercheung@asiaone.com