The driver of a speeding dumper lost control of his vehicle and hit 18 other vehicles before running over and killing a woman and her son eating lunch on a footpath at Jogesh-wari-Vikhroli Link Road (JVLR) on Friday.
Six others were injured in the accident.
The driver was traced a few hours later, police said. The MIDC police said the incident occurred around 1.30 pm, close to the Durga Nagar junction at JVLR.
The police said the dumper first hit a motorbike, four autos, a van and a taxi, after which it hit Chandrabhabha Jadhav, 50, and her son, Arun, 35.
It then went on to hit an Innova which hit a Swift Dzire ahead of it, leading to a trail of around nine damaged cars.