As I'm sure you've heard, Amy Winehouse joins many other musicians who died at age 27. Jim Morrison, Janice Joplin, Jimi Hendrix and Kurt Cobain all died at 27.
While some of them died by their own hand making dying at 27 not so much a coincidence but a choice, there are many others that met that fate from other circumstances. Like Mia Zapata, a Seattle singer who was murdered.
The list is here.