My mid 2012 is frozen while backing up photo library, spinning wheel

My MacBook Pro has been running very slow lately. I often get the spinning color wheel. This morning I am attempting to back up important files to an external hard drive. While copying my iPhoto library to the hard drive, everything has frozen midstream and computer is not responding to any commands. Thoughts? oh and this morning when turning on my laptop, heard a crunching noise from the keyboard.