Police are investigating today's fatal pickup truck crash on Nu'uanu Pali Drive as an "unattended death" rather than a traffic accident due to an apparent suicide note found in the vehicle.

Final disposition of the case is pending an autopsy tomorrow.

The Honolulu Medical Examiner's office is not releasing a name until the identity of the 35-year-old man killed in the crash is confirmed.

The man was the lone occupant in the 1998 Ford pickup, which was headed south on Nu'uanu Pali Drive when it veered to the left of the roadway and collided head-on with a large tree about a half-mile north of Pali Highway at 10:05 a.m., according to vehicular homicide investigator Sgt. Danny Kaholokula.

The case was referred to the Criminal Investigation Division due to "other circumstances," Kaholokula said.