The victims of Wednesday's fatal railway collision between a car and an express train have been identified as two women aged in their 70s.

A 71-year-old and a 73-year-old, both from Camberwell in Melbourne's east, were killed as their car was crushed beyond recognition at Surrey Hills station about 4pm.

Witnesses said the car appeared to have been halfway through Union Road level crossing before the boomgates came down around it.

The car was dragged underneath the train for about 100 metres, before being pushed against the platform.