The encierro (bull run) of San Sebastián de los Reyes, held annually at the end of August, is ranked the second most popular in Spain, right after the encierro of San Fermin held a month earlier at Pamplona.

A (typically unidentified) video of the 2005 disaster in which 63 people were injured is circulating currently as an Internet curiosity.

2:15 video

Hat tip to JonHenke.