From https://www.pepperdine.edu/waves-of-flags/
Waves of Flags
Each September, Pepperdine stages the Waves of Flags display honoring the lives lost in the terrorist attacks of September 11, 2001, with nearly 3,000 flags in Alumni Park along Pacific Coast Highway and Malibu Canyon Road—one for each innocent victim, including a national flag for each foreign country that lost a citizen in the attack.
Started by students in 2008, Waves of Flags has become a Pepperdine tradition, one that attracts attention and admiration from across the country. It has come to transcend the commemoration of a single tragic day. The display educates both students and people far beyond our campus about the history of our country and the overwhelming sacrifices that heroic men and women have made to keep it safe, prosperous, and free.
Waves of Flags will be on display from Thursday, September 9, to Saturday, September 25, 2021.