The first person to rush to help the teenage victims of the horrific hit and run in Braddon on Sunday morning says he was woken by a slapping sound, followed by screams.
Police have still not found any trace of the white ute that hit two teenagers walking along Henty Street, just behind the Canberra Rex Hotel, about 5.30am.
The crime left Burma Han, described by friends as a caring and fun-loving 19-year-old, with serious injuries to his head and neck.
He was flown to Prince of Wales Hospital in Sydney for specialist care, where he is understood to be in an induced coma. A second youth was also taken to Canberra Hospital with less severe injuries.
As the police hunt for the driver moves into its fourth day on Wednesday, a nearby resident has told Fairfax Media of rushing to the aid of the teenagers.
Anthony Carlson was woken by a slapping sound, and screaming and yelling.
Mr Carlson said he thought there had been a fight, which he says are common during the early hours of the morning.
But as soon as he saw the two youths, Mr Carlson, who was trained in first aid while in the Australian Defence Force, knew something was seriously wrong.
''They were both flat on the ground, face down, both their heads facing towards the cars and the gutter,'' he said.
''One wasn't moving but there was no blood, whereas the kid who was really hurt, there was quite a substantial amount of blood.
''As soon as I realised that I went straight back into the house and grabbed some towels,'' he said.
Mr Carlson said two youths who were walking with the victims but on the other side of the road were in shock.
He gave them glasses of water and waited with them as officers with the Collision Investigation and Reconstruction Team finished their initial investigations.
''I must give the cops heaps of credit too, they were fantastic. The guys on scene and the traffic inspectors afterwards, they were just really friendly and caring,'' he said.
Authorities are pleading with the public to help track the offending vehicle, which they believe deliberately accelerated at the teenagers before running them down and fleeing the scene.
They are searching for a white ute with a trayback with silver sides. It probably has damage to its left front-hand side.
Anyone with information should contact Crime Stoppers on 1800 333 000 or via the website.