Fire crews were at the scene of a Level 2 Hazmat an office building located in the Loop downtown.

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The chlorine leak was reported just after 10 a.m. Friday on the roof of a building located at 77 W. Wacker.

The Hazmat was quickly upgraded to a Level 2.

The Chicago Fire Department reports six people have been transported to Northwestern Hospital and one person refused.

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Chlorine Leak in an Office in the Loop sent six to the hospital AP Photo/Nam Y. Huh