This class teaches people to act as first responders in a mass shooting

(CNN)Yvonne Bubienko stands over a flesh-colored dummy leg that appears to have suffered a deep and severe laceration. She takes an unrolled length of gauze and packs it deeper and deeper into the wound, filling the empty space beneath the surface of the skin. “I’m going to ask a provocative question,” Garrett says. “How many of you are comfortable touching someone else’s blood that you don’t know without gloves?” Almost no one reacts. “Notice that my hand’s not going up,” Garrett says, adding that — if possible — they should wear gloves to prevent the spread of blood-borne diseases. The first step, Garrett says, is to apply direct pressure to the wound, he tells the class, which can take care …