(Trent Nelson | The Salt Lake Tribune) Salt Lake City Mayor Erin Mendenhall puts a mask on following a news conference regarding masks in schools in Salt Lake City on Monday, Sept. 13, 2021.(Trent Nelson | The Salt Lake Tribune) Salt Lake City Mayor Erin Mendenhall speaks at a news conference regarding masks in schools in Salt Lake City on Monday, Sept. 13, 2021.(Trent Nelson | The Salt Lake Tribune) Salt Lake City Mayor Erin Mendenhall speaks at a news conference regarding masks in schools in Salt Lake City on Monday, Sept. 13, 2021.(Trent Nelson | The Salt Lake Tribune) Salt Lake City Mayor Erin Mendenhall speaks at a news conference regarding masks in schools in Salt Lake City on Monday, Sept. 13, 2021.(Trent Nelson | The Salt Lake Tribune) Salt Lake City Mayor Erin Mendenhall speaks at a news conference regarding masks in schools in Salt Lake City on Monday, Sept. 13, 2021.(Trent Nelson | The Salt Lake Tribune) Salt Lake City Mayor Erin Mendenhall arrives at a news conference regarding masks in schools in Salt Lake City on Monday, Sept. 13, 2021.(Trent Nelson | The Salt Lake Tribune) Salt Lake City Mayor Erin Mendenhall arrives at a news conference regarding masks in schools in Salt Lake City on Monday, Sept. 13, 2021.