The Santa Clara County Sheriff's Office was investigating a fatal collision in Cupertino Tuesday involving a pedestrian and a big-rig, a Santa Clara County sheriff's sergeant said.

A woman was struck and killed around 7 a.m. near North Foothill Boulevard and Cupertino Road, sheriff's Sgt. Jose Cardoza said.

The woman, whose age and identity have yet to be released, was starting to cross North Foothill Boulevard heading west at the same time a southbound big-rig was approaching.

The driver of the big-rig is being cooperative in the investigation, and it does not appear drugs or alcohol played a role in the accident, Cardoza said.

Southbound lanes of North Foothill Boulevard were closed after the accident.