alternator question

[btmed]

wifes x5 01, 3.0 was making screetching noise with faint rubber smell on the way home yesterday. i get home this morning thinking thrown belt or maybe tensioner bad. it was dead last night when she tried to move it. first look belt is still in place but i can remove without releasing tension. 1 tensioner was replaced last year. both spin but not freely.
Question, for those that have replaced their alternator, did the alternator freeze up or make a screeching or rattling sound on its last days? this alt is still spinning freely. Going for replacement tensioners and new belt and hoping its not alt. looking for upgrade to 09 or 10 this week.