This article is a qualitative investigation of teachers' pedagogical approaches to the terror attacks on September 11, 2001. The ten participants are regionally diverse in-service teachers who attended workshops conducted by the 9/11 Memorial Museum and Gilder Lehrman Institute of American History in New York during June and July, 2019. Teachers presented their 9/11 lessons at a March 5, 2020 conference in New York City to pre- and in-service teachers. Surveys, interviews, and lessons determined how teachers implemented professional development in their schools. The paper seeks to improve teacher training through the use of primary sources and place-based education to engender student inquiry. The creation of 9/11 digital lesson plans on the Library of Congress' Teaching with Primary Sources site provides teachers access to ensure that 9/11 receives greater emphasis in the social studies curriculum. Findings indicate that in-situ, place-based experiences increased 9/11 curriculum in classrooms.