CHICAGO (AP) — Thousands of people decked out in green have descended on downtown Chicago for St. Patrick's Day festivities.

The crowd lining the Chicago River let out a collective cheer Saturday as workers on a boat dumped dye into the water, turning it a fluorescent hue of green — at least for a few hours.

In a sea of people wearing green shirts, coats and even wigs and beards, 29-year-old Ben May managed to stand out. The Elkhart, Ind., man was wearing a full leprechaun costume complete with a tall green hat he had to hold on to in the wind.