Methods and structure for preventing lower page corruption in flash memory. One embodiment is a flash storage device that includes Multi-Level Cell (MLC) flash memory, Single-Level Cell (SLC) flash memory, and a controller coupled to the MLC flash memory and the SLC flash memory. The controller is configured to program host data to a lower page of the MLC flash memory, to generate an erasure code for the host data, and to store the erasure code in the SLC flash memory. The controller is also configured to detect an interrupted write operation to an upper page linked to the lower page, to retrieve the erasure code from the SLC flash memory, and to correct the host data of the lower page of the MLC flash memory using the erasure code.