How L.A. architect Paul Murdoch designed a 9/11 memorial that literally sings

When Paul Murdoch received the commission to design the Flight 93 National Memorial in 2005, he never imagined the job’s final stages would be taken up with figuring out how to build a massive — and massively complex — musical instrument.

The memorial marks the site in Western Pennsylvania where United Flight 93 struck the earth on the morning of Sept. 11, 2001, killing everyone aboard. Flight 93 was originally destined to travel to San Francisco from Newark, N.J., but Al Qaeda hijackers seized control of the aircraft after takeoff and redirected the plane toward Washington, D.C., where it is believed they planned to attack the U.S. Capitol.