A minute's silence will be observed in Wales today on the 50th anniversary of the Aberfan disaster.
Destroyer HMS Duncan Docks In Cardiff
Security is being stepped up in south Wales as warships from around the world come to Cardiff Bay.
Hundreds of people gathered to watch British naval ship HMS Duncan dock at Roath Basin.
Due at 1pm, it was eventually towed in just after 2.30pm.
The massive Type 45 Destroyer is one of several vessels here for the NATO Summit.
A Latvian minehunter docked yesterday, with Dutch and Lithuanian minesweepers, a superfast missile patrol boat from Norway and an anti-submarine destroyer from France yet to dock.
On board these ships are billions of pounds worth of weaponry and radars to help with security off-land.
They're also housing military helicopters.
Assistant Chief Constable Chris Armitt's in charge of the police operation and says we're on high alert for a potential terror threat:
"We've got 67 world leaders coming to this is event, which is an awful lot of very important people in one place at one time"
"It's an event that's been widely publicised so people know they're coming here and that in itself creates security implications"
Nearly 10,000 police officers have already been drafted in for the summit and they're also getting help from the Army.
Barack Obama arrives in south Wales on Wednesday.
Tragedy struck in the village of Aberfan 50 years ago - here's how the disaster unfolded.
Even with the coal tips removed, the landscape of Aberfan still lives in the shadow of tragedy.
50 years after the Aberfan disaster these photos remain some of the most haunting and iconic images.
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