Chris Cornell, the powerful, dynamic singer whose band Soundgarden was one of the architects of grunge music, has died at 52. Cornell died Wednesday night in Detroit, said his representative, Brian Bumbery, in a statement that called the death “sudden and unexpected” and that said the singer’s family would be “working closely with the medical examiner to determine the cause.” Chris Cornell was born in 1964 in Seattle and helped form Soundgarden 20 years later. Sub Pop, then a fledgling record label, released the group’s first single, “Hunted Down,” in 1987, as well as two subsequent EPs. The group’s debut album, “Ultramega OK,” came a year later.