Emergency and police officials in boats and vehicles respond as Greenpeace activists hang off of the West End Bridge, one of Pittsburgh's iconic bridges with a massive banner displaying a message to G20 leaders gathering for the September 24 summit. The banner, nearly 80-feet by 30-feet (24 meters by 9 meters) in size, take the form of a stylized 'road sign' warning of the political maneuvering and delays that have put a international climate treaty in jeopardy as the world enters the final stretch on the road to Copenhagen.