Counties Manukau police spokeswoman Ana-Mari Gates-Bowey said the Serious Crash Unit attended the scene and spoke to a number of witnesses.
Mower's death is the fifth to rock the South Auckland community in recent weeks.
Earlier this month, Ashley Foley, 19, Alan Jones, 18, and Liam Jackson, 18, were killed driving home from Hamilton.
The latter two were friends of Mower.
Last weekend, Viliamu Tavalea, 31, collapsed and died during a rugby game.
Next week also marks the anniversary of the death of Jacinta Waipouri, 19, who was hit by a car after an argument on the Whitford-Maraetai Rd, also in South Auckland.
Waipouri walked on to the road after an argument with her boyfriend and sat down. Her friend, Helen Dando, went to comfort her and both women were struck by a car.
Dando survived with a broken leg, arm, hand and nose.