A 71-year-old Medford man died Thursday morning when the commercial truck he was driving went off Interstate 5 three miles north of Glendale and hit a tree, Oregon State Police troopers said this morning. Bruce Merrill was driving a 2013 Freightliner north around 11:40 a.m. when he for an unknown reason he crossed the southbound lanes, went through a ditch and struck a tree. He was pronounced dead at the scene. Troopers from Grants Pass said Merrill was wearing a seat belt. They are continuing to investigate the cause of the crash. The highway was not blocked. …