Four people were crushed in a stampede at a Halloween party . The women were among thousands of attendees at `` Thriller Music Park , '' an event at Madrid Arena that featured electronic music artists and a costume contest . Three survived , and two are in serious condition . The events at the Arena included electronic music and a costume contest .
Four people were crushed in a stampede at a Halloween party . Three survived , and two are in serious condition . The events at the Arena included electronic music and a costume contest .