Devices and techniques for fatal error logging in a memory device are described herein. For example, a read request can be received for a component of the memory device. A fatal error indication of an error that prevents correct execution of read request can be detected. Diagnostic information for the failure indication can be collected. A response to the read request can then be made with a portion of the diagnostic information as payload instead of the user data that would have occupied the payload had the read succeeded. Metadata in the response can be used to communicate an error code.