An elevator safety system includes: an electronic safety controller; at least one safety sensor providing safety-related information; at least one dual-channel safety node communicatively connected to the safety controller and configured to obtain safety-related information from the at least one safety sensor; and a safety diagnostics configured to: detect a single-channel failure of the at least one dual-channel safety node, and in response to detecting a single-channel failure, determine integrity of the obtained safety-related information. In case the safety-related information was determined intact, the safety controller is configured to generate a command allowing a rescue run of an elevator car to a rescue floor using said safety-related information. An elevator system and an elevator car rescue run method are also disclosed.