Hi - Unfortunately, I can not be certain of your Norway Spruce's problem.

Check around the dying branches and look for places where the tree is leaking white resin (sap). If you see this, you probably have Cytospora canker.  http://extension.illinois.edu/focus/index.cfm?problem=cytospora-canker-of-spruce

Another possibility is Armillaria root rot, however, Norway Spruce is fairly resistant to this disease.http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/spruce-tree-diseases/armillaria-root-ro...

If these aren't the answer, then flip through the slide show to see if you can find your problem: http://files.dnr.state.mn.us/assistance/backyard/treecare/forest_health/whitesprucediagnosis.pdf