Here is the specific incident it looks like that killed the Korean girls.
http://en.wikipedia.org/wiki/Yangju_highway_incident
Looks like the girls got hit by a 57-ton armored bridging vehicle (Ouch!!!) while walking along a narrow road.
The singer was expressing the rage that the country felt 8-years ago over the incident. Freedom of speech is just that and we should respect that. Do we really need to keep harping on things that happened in the past? I am sure that if we went back 8-years on those board we could probably dredge up something on anyone that has been around that long that they probably regret that they said.