This was an American WWII ship that wrecked in the Thames Estuary, carrying 1,400 tons of explosives. It’s monitored by the British Maritime and Coastguard Agency, but something as simple as a collision, an attack or a shift in the seafloor could detonate the bombs.

While it won’t end the world, it would take out a significant part of the English coast. Plus, this is just one of several ‘unstable’ resting places of armaments from WWII that dot Europe.