Rhys Wilson (52) was behind the wheel of a concrete truck involved in a head-on crash with the vehicle full of 16- and 17-year-old boys soon after 4pm on Friday along Queens Dr.
The Invercargill resident was seen sitting on the berm beside the crash site with his head in his hands crying shortly after 3pm on Saturday.
"Yeah, I was back there just trying to get some closure so that was all," Wilson told The New Zealand Herald.
When asked how he had been coping since the accident the truck driver admitted it had been "pretty rough".
"You know, I've got some good support. I'm well. I'm getting better. I just feel sorry for the people in the car so … but I can't do anything about that," Wilson said.
"I'm okay ... I'm recovering with friends and family. That's about all that people need to know."
Police have named the four boys who died as Konnor Steele (16), Indaka Rouse (16), Kyah Kennedy (16) all from Bluff, and O Maruhuatau Otuwhare Tawhai (17) from Invercargill.
Wilson was also keen to correct earlier media reports that he had been hospitalised after the crash.
"It's hard enough as it is. I'm okay. Despite what the media have actually said, that I was in hospital, but I wasn't," he said.
"It was reported that three people [were] in the truck and there was only me. And it was reported that I was taken to hospital and I wasn't. I was checked over, a few bumps and bruises and that's it."
The four friends were in a Ford Ranger ute when it and the truck collided on a marked 50km/h inner-city road in wet conditions. Police are still investigating the circumstances.
Invercargill surgeon Dr Julian Speight was driving one of the first cars to arrive at the scene after the accident.
"It was a very cold and wet and miserable evening and I was just on my way home from the hospital ... I was probably about eight or 10 cars back from where the accident occurred," Speight said.
"I arrived maybe two or three minutes after the crash and there was already a nurse on scene who had both ED and ICU training. She was doing a fantastic job. She had already assessed all the people in the vehicle and had identified one patient who was potentially saveable."
A bystander found a wrench from the truck which was used to jimmy open the back rear door of the ute furthest from the truck at which point a patient assessed by the nurse to still have a pulse was initially found.
"The doors on the driver's side on the non-impact side were buckled and we were initially unable to open them," Speight said.
"In the interim, the nurse who was there was doing an excellent job maintaining his airway in the car. So we did what we could before the arrival of the ambulance but the ambulance was there very quickly."
Speight said, however, it was quickly identified that even that occupant "unfortunately transpired to have too severe injuries".
"I just helped out as best I could. We were just managing that patient until the ambulance arrived - which arrived pretty quickly.
"It was evident pretty soon after that the patient was actually not going to survive either."
Speight said it was a "hectic" scene when he arrived at the crash site and they were struggling to get access to any of the patients.
"It's very sad. It's a terrible tragedy for Southland and my thoughts are with families at this difficult time," he said.
"But unfortunately there was nothing that could be done for any of the occupants of the vehicle. It was too severe an impact."
It has also emerged that the road on which the accident occurred had been resealed in March.
The Invercargill City Council said at the time on its Facebook page, Invercargill Word on the Street, that the reseal was the second phase of roadworks on Queens Dr.
The road was closed for the resealing on March 5 from Herbert St to Gala St and included the Queens Dr entrance to Queens Park.
Residents along Queens Dr have described the street as slippery since the reseal job.
Nathan Tane lives along Queens Dr and rushed out of his house at the huge sound of the crash and began helping to redirect the swiftly building traffic away from the scene.
"They called it rejuvenating [the road]. It's real slippery when it's wet. In fact, just yesterday we heard it about three times - just cars or trucks coming to stop and there's squealing. We heard skids, just people trying to stop in time for the lights. So new surface and rain and heavy vehicles."
Tane said emergency services were working at the site into the early hours of Saturday morning. He said hearses arrived at the scene about 10pm on Friday.
Tane had moved road cones from his home renovation on to the street to block the cars.
"We just put them on the street and everyone was really good," he said.
Kath McGoldrick was working as a carer in a house directly across from the accident when it happened and was also among the first responders.
"The bang was horrific. The noise of the truck pushing the vehicle down the road was horrific and the faces of the young boys - they are in my memory.
"As closure for it all I went over [the next day] and brought some flowers and placed them on the side of the road.
"I just feel so incredibly sad for the families of the young boys. And I feel intensely sad for the poor driver of the truck. It was just so horrendous and I just feel bad for him."