Error correction in a disk drive is performed by error correction circuitry which accepts data read from a data storage medium. The error correction circuitry performs both block error correction in a first data domain and sector error correction in a second data domain. A sector FIFO buffer is used to facilitate the error correction in real time, or "on-the-fly." The sector FIFO buffer also enables conversion of the corrected data to the first data domain. The error correction circuitry also generates an ECC block comprising a plurality of sectors and writes the ECC block. The circuitry generates a tag prior to writing the ECC block and adds the tag to each of a plurality of sectors. During a read operation, the circuitry detects a write disruption when the tags for all of the plurality of sectors in the ECC block are not identical.