May 20, 2012 – (Above) At 4:41 p.m. on Saturday, thousands of protestors walking south on Michigan Avenue approach Chicago police officers waiting for them at Congress Parkway. (Click on images to view larger versions.)

For several tense minutes, police blocked the protestors from crossing Congress Parkway.

18th district police commander Kenneth Angarone (second from left) is briefed by his officers.

With four helicopters hovering overhead and the crowd chanting, “The whole world is watching,” Chicago police decide what to do with the protestors who clearly want to cross Congress Parkway. At 4:49 p.m., the crowd was peacefully allowed to cross and by 5:07 p.m., they had all reached Roosevelt Road.

Earlier in the afternoon, a Coast Guard patrol boat guarded the west side of the DuSable Bridge.

The Shoreline vessel Evening Star is momentarily blocked by a Chicago police boat from going under the Wabash Avenue Bridge.

(Above) Overhead view of the Coast Guard boat.	With Marina City in the background, a foreign television journalist reports from Wacker Drive.

(Left) A police horse in riot gear prepares to block Michigan Avenue from thousands of protestors. Audio: Two-minute wild track from Chicago NATO protest. Duration: 2:00.