Jagseer Boparai was driving to work in wet conditions at about 2am when he veered off Cross Keys Road in Salisbury.
His vehicle then careered into a tree, a bus shelter and then a Stobie pole.
The 37-year-old was killed on impact.
“I heard like a thunder at first and then Draco decided to bark because he felt something else was strange,” witness Pamela Arakaza said.
Boparai was planning to travel back to India with his brother in December, where Jagseer would be reunited with his fiancée, to then get married.
“I can’t imagine how his partner would feel,” nearby resident Duhsak Lal said.
“They’re a few days or maybe months away from having the happiest moment of their life and now all that is taken away.”
Major crash detectives carried out their investigations, resulting in Cross Keys Road remaining closed into the afternoon, while nearby onlookers found it difficult to process the distressing scene.
“We can’t even open the gates. We can’t go to church either and we’re just stuck here just looking at this scene every now and then,” Lal said.
SA Power Networks crews began work on reconnecting nearby homes and businesses after the Stobie pole was bent 90 degrees in the crash.
