Employees encountered a soul-crushing scene on Thursday when they arrived at the American National Insurance building in Galveston, Texas: 395 dead or dying birds.
The migrating birds had crashed into the 23-story building — the highest in the city — after flying across the Gulf of Mexico, the Houston Chronicle reports. They were heading north toward their nesting grounds, Sarah Flournoy of the Houston Audubon Society told the publication.
The group included some 25 species, mostly brightly colored yellow and orange Nashville and Blackburnian warblers, but there were also redstarts, ovenbirds and orioles.
“This is the largest event like this I have ever been a part of in over 10 years,” Galveston Police animal services supervisor Josh Henderson told the Chronicle.
Bird experts say the tragedy was likely caused by a combination of high winds and the building’s bright lights, which could have looked like moonlight or the sun to the flock, according to The Guardian. The wind had also probably forced the birds to fly lower than usual. It’s not clear whether the birds were all flying together when they hit the building.
Flournoy said it would help birds if office buildings turned off their lights at night, at least during migration season.
The birds’ bodies will be sent to university labs where researchers will check health, size and DNA, The Guardian reports.
The three surviving birds that were found were taken to a wildlife rehab center to recover, according to the Chronicle.