The boy was identified as Allahuddin Sawat (16), a resident of Bainganwadi, while the 55-year-old deceased was yet to be identified, police said.
According to police, the elderly man was walking on the GML Road when a speeding dumper lost its control and hit the victim at 3.40 pm yesterday.
The profusely bleeding victim was rushed to a nearby civic-run Rajawadi hospital, where he was declared brought dead, police said.
"The driver left the vehicle and ran away from the spot," said P T Panaskar, senior inspector at Deonar police station.
In another incident on the same road, Sawat was crushed to death by a speeding trailer while he was crossing the street at 6.30 pm yesterday, Panaskar said adding that, "After the accident, the driver fled with the vehicle."
The body of the minor victim was taken to Sion hospital for post mortem, police said.
A hunt has been launched to trace the accused; police said adding that further probe was on.
