A man has been arrested on drunk driving charges after hitting a pedestrian in Nassau County Thursday afternoon.

Niall Duignan, 24, of Oceanside, was driving a 2004 Chevrolet Express Van when he struck a woman who was walking on Long Beach Road in Oceanside around 4:30 p.m., according to police.

The 78-year-old victim was taken to an area hospital where she is listed in critical condition.

Detectives tell News 12 the pedestrian was crossing the road at the crosswalk near Weidner Avenue when she was struck.

An investigation revealed that Duignan was operating the vehicle while intoxicated and he was placed under arrest at the scene.

He will face charges of DWI and vehicular assault when he is arraigned Friday.