water damaged froze when restarting

The phone froze when a call came through so I restarted the phone but it froze up on the metro pcs logo ,then when I took off the back cover I noticed that the water damage indicator turned red but it didn't get wet so could moisture somehow got into the phone ? Also before the call came through the internal memory got full stating that I needed to make space because I was recording a video when the phone call came through but the phone was working fine until that so what could this be? And how can I get files from my phone when all it does is freeze on the metro pcs logo when I cut the phone on ?????