The Boston Marathon bombings that occurred near the finish line on April 15th resulted in serious casualties.

波士顿马拉松爆炸案是2013年4月15日上午在波士顿马拉松比赛接近终点处发生的爆炸事件，该事件造成非常严重的伤亡后果。
新闻例句

美国总统奥巴马要求其政府为周一下午发生的波士顿马拉松赛爆炸案提供一切必要的调查和应对援助。
US President Barack Obama has directed his administration to provide whatever assistance necessary in the investigation and response to the deadly Boston Marathon explosions on Monday afternoon.