Single Microphone into two ADAU1977s

The ADAU1977 has a built-in Microphone input and Mic Bias circuit.  I have a redundant input
into my system to two ADAU1977s.  I have a single microphone that needs to
connect to one input on each ADAU1977.  How can I connect the single
microphone to the two ADAU1977s robustly so that if one of the ADAU1977 dies or
shorts the mic inputs the other ADAU1977 will still operate correctly with the
microphone?