Which member of Metallica was killed in a bus accident in 1986?

Explanation

Metallica is an American heavy metal band formed in Los Angeles in 1981 by, among others, Lars Ulrich (drums) and James Hetfield (lead singer). Their bass player Cliff Burton was killed in a tour bus crash in Sweden in 1986. Metallica's albums include "Kill ´Em All" (1983), "And Justice For All" (1988), "Metallica" (1991), "St. Anger" (2003) and "Death Magnetic" (2008). The production of "St. Anger" was depicted in the documentary "Some Kind of Monster" from 2004.