State Police say a woman died early Friday morning when her vehicle overturned in Sidney.

Public Safety spokesman Steve McCausland says the accident happened on a slight curve on Middle Road just after 8:00. A pickup truck overturned and came to rest on its roof at the intersection with Reynolds Hill Road, less than two miles from the Augusta city limits. Police say that the woman was killed instantly. Her name has been withheld pending notification of kin.

Officials say speed and the fact that the woman was not wearing her seat belt were likely factors in the accident, which remains under investigation.

We'll update this story as more details become available.