It could be sign the drive is failing. I would back up any critical data NOW, then do regular backups there after.
This could also happen if the computer suddenly came to a crashing halt - as caused by a power outage or being turned off without first "gracefully" shutting down Windows, or by a failing power supply, or excess heat. Or any number of other reasons - which makes troubleshooting these type problems difficult, at best.
While it may be a one-time event, I would stay ready for it to happen again. I also recommend opening the side panel and inspect the interior to ensure all fans are spinning, and that there is not a layer of heat trapping dust inside. If full of dust, gracefully shutdown Windows, unplug from the wall, and while touching bare metal of the case to prevent any destructive static discharges, carefully remove the dust (I generally recommend taking the computer outside and blast with compressed air).