The loud "bang" nearby caught the lead cyclist's attention.
When he turned around, he was shocked by what he saw.
His cycling buddy was sprawled on the road. In the distance, a silver lorry was speeding away.
From his hospital bed, the victim identified only as Mr Lau, a 41-year-old sales director, told Lianhe Wanbao what happened.
He said: "One moment, we were cycling and the next, I was on the ground."
Both cyclists were heading towards Changi Village on Thursday when the accident happened at 5.55am near the Changi Cargo Complex on Changi Coast Road.
Mr Lau's pre-dawn incident was first reported on citizen journalism portal Stomp, where his older brother had appealed for witnesses.
The post stated: "The lorry sped off leaving behind some fragments of head/indicator lights." The brother, who is in his mid-40s, was upset at what happened.
He declined to be named but was willing to be interviewed last night. He told The New Paper on Sunday: "I'm disappointed with the driver for not helping (my brother).
Mr Lau's cycling buddy said the driver actually made a U-turn to take a look at the accident scene.
The brother said: "I was fuming mad. He had the cheek to return but didn't help. Later, he just drove off.
"If the driver believes in karma, he should just own up and surrender to the authorities."
He added: "My brother is in a lot of pain. Half his spine is fractured and he has two cracks on his pelvis.
"His spine needs to be stabilised before more operations can be done, doctors have said."
Recovery for Mr Lau will take a long time, he said. He will need a few operations in the coming weeks, said the victim's brother.
Mr Lau now finds it hard to move without help from the nurses.
He said: "I feel like a ragdoll. I can't move my upper body or sit up."
Doctors have told him that he was lucky. If his spinal injuries had been more severe, he could have died, Mr Lau had told Lianhe Wanbao.
In another accident, a collision between two taxis at the junction of Rochor Road and Victoria Street left five people in hospital.
Police said investigations are ongoing and they are appealing for witnesses to call 1800-5471818. On Friday, two road accidents resulting in injury were reported.
An early morning collision involving two taxis at the junction of Rochor Road and Victoria Street landed five people in hospital.
They suffered head injuries and chest pains.
Witnesses said a taxi was going straight, while the other was turning right.
The impact was so severe that one Stomper, in his online post, said the damaged taxi looked like a "crumpled tin can".
That same evening, a car overturned at the entrance to the National University Hospital (NUH) and came to a rest on its right side.
The injured passengers, an 80-year-old woman and a teenage boy, were treated at the hospital's accident and emergency department.
The woman had back and knee injuries, while the teenager had cuts on his fingers. The driver of the car was unhurt.
This article was first published in The New Paper.