Reactions on Twitter have been coming in quickly since a pair of explosions at the finish line of the Boston Marathon on Monday killed two people and injured dozens of others.
Members of the sports world have been checking in with heartfelt statements. College basketball announcer Dick Vitale called the bombings "gutless," "cowardly" and "sick."
NBA superstar LeBron James wondered in a tweet, "WTF is wrong with people man," while NFL legend Jerry Rice asked, "What has this world come to?"
And many more are calling for prayer. Chicago Bears receiver Brandon Marshall said, "Our entire nation should fast & pray for our wicked world," and pro football Hall-of-Famer Cris Carter simply stated, "Pray for them."