A fire that started near Adventist Health Ukiah Valley is being investigated as a case of arson. The Ukiah Valley Fire Authority is pursuing some leads on the grass fire, which was quickly extinguished before it burned more than one-eighth of an acre. The fire was first reported around 5 p.m. Monday, between Baskin-Robbins in the Pear Tree shopping center and the AHUV emergency room. Hospital staff used fire extinguishers to help slow the spread of the fire.