System has been in for years, had help programming from Voyager.
Yesterday someone collapsed and they tried calling 911 and 9911. Both attempts netted a fast busy. I don't have much experience on PRI and Voyager is not available.... any suggestions?

Check Program 550 Enhanced 911. I am assuming that the PRI is not on OLG1, so you should set Prg 550 E911 with the OLG for the PRI.

With many of the local carriers I will be asked to test 911 as part of new service turn up.

Okay, that did it. OLG5 was the PRI.
Thanks for the FIX David!