State College Police responded to the explosion of an Allegheny Power transformer yesterday morning on the 400 block of East Calder Way that showered liquid onto about 40 cars and one person.

Members of the Penn State HazMat Team were called to the scene and concluded that the liquid, identified as mineral oil, was not harmful, police said. The incident, which happened at about 9 a.m., shut down the area to traffic for about an hour.