falling star?

Our apartment has a view because we live on the 20th floor of an apartment building. We see the view of downtown and we sometimes see some fireworks specially when there's an occasion or a concert held downtown. When my hubby showed me this picture in my digicam, it bothers me a lot if it is a firework or what. He said he took it last Sunday afternoon while i was sleeping. I'm just wondering what it is. I just laughed at him when he said that it's a falling star. hehehe...It was taken around 5p.m. so how could it be a falling star? Besides, i don't remember if i've ever seen a star here in Korea. Well, i don't think that it's a firework, either. What on earth is this?