On December 6, 1917, two ships collided in wartime Halifax Harbour, creating what became the largest man-made explosion of its time. More than 2000 people died (500 of those children) and 9,000 were injured. A single little tree whispered from its branches the word “Help” that was carried by the wind to the people of Boston. Within 48 hours Boston and Massachusetts organized trains to carry 33 doctors and 79 nurses. To repay the City of Boston for its generosity, the little tree (which now had become huge and majestic tree) was given to the city of Boston as a way to say thank you, a tradition that continues to this day.