Are you certain that your phone is still working but it's just that your display is gone. Can you see notification lights ?
The same thing happened with my OnePlus, water, rice, charged, no life on display but I could see notification lights. I visited the service centre and they replaced the screen without any damage to data. Same happened with my boss's OnePlus 2 during screen replacement.
I think you still have chance to sent to repair and have the data saved.
Last edited: Oct 10, 2018