The Townsend Thoresen cross-Channel ferry Herald of Free Enterprise capsized outside the Belgian port of Zeebrugge on the 6th of March with the loss of 135 lives.
The ferry experienced rough conditions for 1 hour before capsizing.
( z1 experience :ARG0 ( z2 ferry ) :ARG1 ( z3 condition :ARG1-of ( z4 rough ) ) :duration ( z5 temporal-quantity :quant 1 :unit ( z6 hour ) ) :time ( z7 before :op ( z8 capsize :ARG1 z2 ) ) )