One person is dead and another injured after a semi truck crashed on Interstate 84 on Sunday. Idaho State Police say the commercial vehicle was driving west on the freeway when the driver had a “medical emergency.” The semi drifted into the median and across eastbound lanes of I-84. It then rolled and came to a rest on the freeway shoulder, blocking a eastbound lane and the frontage road south of the interstate. The driver died at the scene and the passenger was able to get out. ISP says both people were wearing seat-belts and is still investigating the crash. On Monday, after family had been notified, ISP identified the driver as Joe Townley Jr, 78, of Anderson, California. The passenger, who was injured, was Mark Zahler, 57, of Brooklyn, New York. Zahler was taken by ground transportation to St. Luke’s Magic Valley Medical Center. The truck was carrying some barrels of oil and there was a small spill in the ditch between the interstate and the frontage road. ISP says a hazmat team is going out to investigate the spill.