Three members of a bomb-disposal squad were killed in 2010 when the device they were trying to defuse in the German town Gottingen went off.

CNN: Experts defuse unexploded WWII bomb in central Berlin

Dr Lassmann and collaborators from the Mayo Clinic in Rochester, Minnesota and the University of Gottingen in Germany gathered tissue samples from 51 patients who had brain biopsies performed during acute flare-ups of MS and 32 who died during acute episodes.

BBC: MS 'may be four different diseases'