The incident occurred around 2 PM when the SUV hit the vehicle, which was lying on the road after being involved in another accident, said Inspector S B Mane of Virar police station.
The victims were on their way to famous Siddhivinayak temple at Prabhadevi in Mumbai.
Prima facie, the driver of the SUV lost control over it while overtaking other vehicles and crashed into the truck, Mane said.
The deceased were identified as Jignesh, Jaiman alias Ameet and Pranay Jaiswal.