 During the bombing raids of the Second World War its library was destroyed, but the cathedral did not sustain extensive bomb damage; the local Fire Wardens doused any flames on the wooden roof.In 1986, a new Martyrdom Altar was installed in the northwest transept, on the spot where Thomas Becket was slain, the first new altar in the cathedral for 448 years.Mounted on the wall above it, there is a metal sculpture by Truro sculptor Giles Blomfield depicting a cross flanked by two bloodstained swords which, together with the shadows they cast, represent the four knights who killed Becket.