Witnesses heard a "huge sound of impact, like metal being compacted" and rushed to help after a twin-cab ute driven by a Canberran smashed into the back of a B-double fuel tanker.
The electricians were working on a nearby Bywong property around 9.40am on Wednesday. The incident happened on the Federal Highway southbound between Donnelly Road and Macs Reef Road, about 7km from the ACT border.
The incident closed both the southbound lanes of the Federal Highway. Police converted the two northbound lanes into single lanes in either direction, diverting the traffic into the newly created lanes at Donnelly Rd.
Electrician Ben Caldwell said he had been working in a shed just off the highway on Wednesday morning when he heard an "enormous" vehicle impact.
The crash occurred just 80 metres away from where the electricians were working.
A blue twin cab ute had ploughed into the back of a fully laden B-double tanker which appeared to be pulling slowly off the highway into a rest area.
"It was a pretty nasty huge impact sound, like metal being compacted," Mr Caldwell said.
"We got there pretty quickly and did what we could to help."
Two people were in the ute, a boy aged 11 and the male driver, aged 40. The boy managed to get clear of the crashed car by himself. He suffered injuries consistent with seatbelt bruising.
The driver was more badly injured and took around 15 minutes to be extricated from the wreckage. Both were taken to hospital. The driver of the truck was not injured.
Both southbound lanes of the Federal Highway remain closed until mid afternoon.
