While the Costa Concordia had the possibility of being a much more serious incident had it been further away from shore, the Guardian lists the most serious shipping disasters (in peacetime) since 1912:
15 April 1912 — Canada
The White Star passenger liner Titanic sank on her maiden voyage off Newfoundland after hitting an iceberg. Of the 2,200 passengers and crew aboard the ship, dubbed before its departure as “unsinkable” 1,523 died.
29 May 1914 — Canada
At least 1,012 people were killed when The Empress of Ireland passenger liner collided with a Norwegian freighter on the St Lawrence River in Canada. It was carrying 1,057 passengers and 420 crew.
[. . .]
29 October 1955 — Soviet Union
The Novorossiysk, formerly the Italian battleship Giulio Cesare, was moored near the shore at Sevastopol. She was the flagship of the Black Sea squadron of the Soviet Navy. The ship exploded and then capsized and sank with the loss of 609 crew.
[. . .]
6 March 1987 — Britain
The car ferry Herald of Free Enterprise capsized and sank shortly after leaving the Belgian port of Zeebrugge. The vessel had 463 passengers and crew on board when it left the port with its bow doors still open. 193 people were killed.
20 December 1987 — Philippines
In the worst peacetime sea tragedy, the ferry Dona Paz sank after colliding with the tanker Vector in the Sibuyan Sea. 4,375 people died on the ferry and 11 of the Vector‘s 13-man crew were killed.
