The former chief executive of the hospital where Lucy Letby murdered seven babies said the board "just didn't see" what was going on when the death rate increased.
Tony Chambers was in charge at the Countess of Chester hospital during 2015 and 2016, when the nurse also attempted to murder seven others infants.
Mr Chambers began giving evidence to the public inquiry into the circumstances around Letby's offending by apologising to the families of her victims.
However he said "there was a strong level of support" for the nurse at the time doctors raised suspicions about her, and that he and his fellow executives were "very reliant on the processes that exist within the hospital".