Most dominoes toppled by a group

Most dominoes toppled by a group
Who
Domino Day 2009
What
4491863 total number
Where
Netherlands (Leeuwarden)
When

On 13 November 2009, Domino Day 2009 saw the world record broken for the most dominoes toppled by a group, when 4,491,863 dominoes were toppled. A total of 89 builders set up the dominoes in the WTC Expo Center in Leeuwarden, Netherlands.