Eight hundred and fifty people took part in a stunt in New Orleans to break the world record for "mattress dominoes". Each person acted as a human domino being knocked over in a chain reaction.
Source
Reuters
UPDATED 9:20 AM - 26 Aug 2013

Eight hundred and fifty people took part in a stunt in New Orleans to break the world record for "mattress dominoes".

Each person acted as a human domino being knocked over in a chain reaction.

More than 850 people took part in the stunt that took several minutes, beating the old record by 300 people.

The mattresses used in this record breaking attempt will be donated to local charities.