Lionel Messi, rest of sports world, react to Barcelona van attack

Emergency workers stand on a blocked street in Barcelona, Spain, Thursday, Aug. 17, 2017. A white van jumped up onto a sidewalk and sped down a pedestrian zone Thursday in Barcelona’s historic Las Ramblas district, swerving from side to side as it plowed into tourists and residents. Police said 13 people were killed and more than 50 wounded in what they called a terror attack. (AP Photo/Manu Fernandez)

A van plowed into a group of pedestrians in Barcelona on Thursday, killing at least 13 and injuring 50.

The sports world, including many current and former FC Barcelona players, reacted to the attack on social media.