Man charged over fatal Melbourne crash

A man has been charged over a crash in Melbourne's west in which a four-year-old boy and 10-year-old girl were killed.

The 41-year-old is charged with negligence causing serious injury and two counts of culpable driving after overtaking a car and then colliding with another at Truganina about midnight on Saturday, police say.

The girl died at the scene and the boy later in hospital.

The man remains in hospital and police will front Melbourne Magistrates Court later on Tuesday seeking that he be held in remand.