46K views · 871 reactions | In 1944, a V-2 rocket hit London with no warning — the first supersonic weapon in history. The explosion was so massive, people thought an earthquake had struck. #BritainAtWar #WW2 #V2Rocket #HistoryShorts #londonblitz#afghanistanvszimbabwe | Britain At War | Facebook

A single warning can change everything. Before the atomic bomb, the Halifax Explosion was the largest human-made blast in history. This Heritage Minute tells the story of Vince Coleman, a railway dispatcher whose final telegraph message in 1917 saved hundreds of lives. Interesting fact: His chilling last words were, "Guess this will be my last message. Good-bye, boys." | Historica Canada

A nuclear warning siren blared across Hawaii for the first time since the end of the Cold War - all because of the threat from North Korea. (Best viewed with the sound on.) (Video: Reuters) | CNA