Bed warped suddenly?

[EagleSeven]

Did you try putting a known Straight-edge, like a metal Ruler, on bed ?
To try to see if it is really warped.

I'm thinking the Tubes, that extruder assembly moves on, may be Bent down in center ?
But I don't see how they could get bent with normal use.
The tubes in our printer have not bent and I've put a Lot of pressure on them during extruder Clean-outs.