Hawaii County officials will conduct an autopsy this week to determine how a 45-year-old Mountain View was killed Friday while walking on Highway 11 near Glenwood.

A negligent homicide investigation has been initiated after Robert S. Silva died at Hilo Medical Center where he was taken following the accident at 7:29 p.m. Friday.

Police said accident occurred near the 20-mile marker in Glenwood.

The victim was in the northbound lane of the roadway when he was hit by a 49-year-old Hilo man who was driving a 1998 Peterbilt water truck and traveling north on Highway 11.

The victim was taken to Hilo Medical Center, where he was pronounced dead at 8:57 p.m.

The driver of the water truck and his 48-year-old wife were not injured.

Puna patrol officers were already en route to the same area in response to a report of a man running on the roadway.

Police do not suspect alcohol, drugs or speed with respect to the driver.

This is the 13th traffic fatality on the Big Island this year compared with 14 at this time last year.

Anyone with information about this crash is asked to call officer Tuckloy Aurello at (808) 961-8119.