As part of Sustainability Week in 2011, SPEAK (Students Promoting Environmental Acton in Knoxville) held a Coal Kills flash mob on the pedestrian mall. At 12:15 p.m. on October 13, a horn was blown and students fell to the ground and shouted out a fact about coal and its harmful effects. After the flash, students marched to the chancellor’s office carrying posters and signs urging UT to replace its use of coal and adopt green measures, moving to 100 percent use of clean energy.