Tangled History: The Boston Marathon Bombing

It was a beautiful spring morning. Thousands of runners were gathered at the starting line of the Boston Marathon. No one could imagine that the glorious day would be shattered by two bombs placed at the finish line that afternoon. Those bombs would leave 250 people injured and four people dead. Follow the events as they occurred, told from multiple viewpoints of people who were there, in this riveting account of a day that left "Boston Strong".