A US Airways Express flight crew reported seeing what looked like a flare with a smoke trail in the vicinity of its aircraft while on approach to Philadelphia International Airport on Tuesday.
According to authorities, what the crew witnessed remains a mystery.
Law enforcement authorities are investigating the incident.
Tip: @cnnbrk on Twitter
Not much more to go on here. Just a curious incident being investigated. Fireworks? Flares? Who knows? But they might get in some big trouble.