According to the police, Jamuna Kodandaraman (37), was riding the vehicle with her son Kamesh (18) on the pillion.
The duo were residents of Otteri and were going to attend a function at Vedanthangal near Chengalpet.
Kamesh was pursuing his first year of BCA at a private college in Tiruvallur.
At 6.40 am, when they reached Retteri near the Porur double-lane, their vehicle hit against a parked lorry.
The police said, "The lorry was parked on the left side of the road and driver Rajasekar (37) was fixing a faulty wire of the vehicle. The heavy vehicle was parked at a no-parking spot."
Jamuna’s two-wheeler rammed against the rear side of the lorry. The police said Jamuna and her son were not wearing helmets. They sent the bodies to Government Kilpauk Hospital for post-mortem.
The police took into custody Rajasekar who is from Cuddalore.