Despite the Tribute in Light's magical beauty, it's actually dangerous for birds, who can get confused and caught in the light beams. Like last year, New York City Audubon sent volunteers to the lights to monitor migrating birds and periodically request for the lights to be turned off.

After all, it's 88 7,000-watt lights.

Here's how the Audubon Society explained the phenomenon:

For reasons still unknown to science, artificial light attracts birds, from fledgling seabirds to migrating songbirds (it does the same to moths). Once captivated, disoriented birds may crash into windows, or spend hours circling.

The 9/11 tribute is particularly problematic: dozens of 7,000-watt bulbs allow it to reach four miles into the sky—it’s visible from 60 miles away. So New York City Audubon members and volunteers take two-hour shifts underneath, scanning the beams, counting birds. Every time 1,000 birds or more are circling—or an exhausted bird falls to the ground—they alert the National September 11 Memorial and Museum (who runs the tribute), which immediately turns off the lights for 20 minutes, giving birds a chance to clear the area.

And birds weren't the only ones swirling around up there—there were also...BATS:

All in a day's work:

NYC Audubon says that 9/11 survivors have volunteered to help with monitoring; according to conservation biologist Debra Kriensky, they "have told me the last thing they want from this memorial, which is so meaningful and beautiful…is for there to be more death on this spot."