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Scott Sommerdorf | The Salt Lake Tribune More than 4,000 people -- many of them wearing surgical masks -- came to the Utah Stat Scott Sommerdorf | The Salt Lake Tribune Three-year-old Sammy Murray of Sandy had a message for legislators as he attended the Scott Sommerdorf | The Salt Lake Tribune As demonstrators gathered at the capitol, a power plant to the west of Salt Lake City Scott Sommerdorf | The Salt Lake Tribune Esther Fors, right, sings along with the other "Smog Lake Singers." More tha Francisco Kjolseth | The Salt Lake Tribune Kent Burningham joins thousands of clean air advocates as they gather on the steps of Scott Sommerdorf | The Salt Lake Tribune More than 4,000 people came to the Utah State Capitol building to protest the unhealth Scott Sommerdorf | The Salt Lake Tribune A demonstrator brought his dog with its own face mask. More than 4,000 people came to Scott Sommerdorf | The Salt Lake Tribune More than 4,000 people came to the Utah State Capitol building to protest the unhealth Scott Sommerdorf | The Salt Lake Tribune Matt Pacenza, of HEAL Utah, speaks on the Capitol steps as more than 4,000 people came Scott Sommerdorf | The Salt Lake Tribune Two-year-old Norah Ricker claps as she sits on the shoulder of her mother, Suzy Ricker Francisco Kjolseth | The Salt Lake Tribune Thousands of clean air advocates gather on the steps of the Capitol to push for pollu Scott Sommerdorf | The Salt Lake Tribune More than 4,000 people - many of them wearing surgical masks - came to the Utah State Francisco Kjolseth | The Salt Lake Tribune Thousands of clean air advocates gather on the steps of the Capitol to push for pollu Scott Sommerdorf | The Salt Lake Tribune More than 4,000 people who came to the Utah State Capitol to protest the unhealthy air Scott Sommerdorf | The Salt Lake Tribune More than 4,000 people came to the Utah State Capitol building to protest the unhealth