Police have charged a 17-year-old Wannanup boy with serious traffic offences after a fatal crash in Falcon on New Years Day.

The crash happened just after 1am as the youth was driving a Holden Commodore north on the Old Coast Road, near the intersection of Pleasant View Circle.

It will be alleged the youth was using a mobile phone to illuminate the car's faulty instrument lights by intermittently activating the keys.

The car struck a group of pedestrians, some of whom were walking near the kerb on the roadway.

The driver failed to stop at the crash scene and continued on to his home address, where his family later contacted police.

Three men were taken to hospital, where a 19-year-old Mandurah man died the following day from his injuries.

The boy has been charged with dangerous driving causing death, two counts of dangerous driving causing bodily harm, failing to stop after a crash, failing to render assistance, failing to report a crash and excess 0.08.

He will appear in the Mandurah Children's Court on August 3.

PERTH