Did my iPhone die?

I plugged in my iPhone 5 to charge last night and went to sleep. When I woke up this morning I unplugged it and pressed the home screen to see what time it was, but the screen remained black. I ve tried plugging the phone into different outlets with different chargers with no response. I even plugged the phone in to my computer and got no response. This has happened to me a couple times before, and I was able to fix it by pressing and holding the lock and home buttons at the same time. However, my lock button is broken. is there anything I can do or is my phone dead?