NATION IN BRIEF : SOUTH CAROLINA : Train Crash Probe Focuses on Switch

A switch at the spot where an Amtrak train derailed was not locked into position after the accident, an official in Camden, S. C., said. Federal officials said it has not been determined whether the switch was locked in position, as it should have been, before the train rode over it early Wednesday. The switch, a mechanism that directs trains from one track to another, should be locked into position to operate properly. Authorities were also investigating reports that rescuers were slow in responding to the wreck, in which seven people were killed.