Tribute in Light

Tribute in Light began as a temporary commemoration of the attacks in early 2002, but it became an annual event, currently produced on September 11 by the Municipal Art Society of New York.

[6] The Tribute's illumination begins at dusk and ends at dawn, with the lights being turned off for 20-minute periods to allow migratory birds to escape as needed.

On clear nights, the lights can be seen from 60 miles (97 km) away,[7] visible in all of New York City and most of suburban Northern New Jersey and Long Island.

[9] A similar Tribute in Light has also appeared on occasion at the Pentagon in Arlington County, Virginia and at the crash site of United 93 in Shanksville, Pennsylvania, which were also targeted during the 9/11 attacks.

During a testing phase of several days, observers in Brooklyn, Staten Island, New Jersey, and uptown Manhattan help make sure that the beams are adjusted accurately.

[17] A permanent fixture of the Tribute in Light was at one point intended to be installed on the roof of One World Trade Center,[18][19] but it was not included in the finished design.

[24] A 2017 study found that the installation "dramatically altered multiple behaviors of nocturnally migrating birds—but these effects disappeared when lights were extinguished".