The Panasonic NCR18650PD, -PF, CGR18650CH and almost any IMR cell (Samsung 20R, Sony VTC etc.) DONT have a PTC. The PTC disconnects when the temperature gets too high but also limits the current. The NCR18650PD is not much different from the NCR18650, except for the missing PTC.
The 0.00V cell might have the CID (current interrupt device) triggered, it disconnects the cell when internal pressure is too high. A high internal pressure is a pretty bad sign..
The CID usually doesnt reset itself, unlike the PTC.
Then, there is the pressure valve. Thats the next step. Directly under the positive pole, its a predetermined breaking point, you can actually see it here:
its the grid-like thing in the middle. Its the last safety feature to trigger and breaks when internal pressure gets way too high because of temperature or similar. The cell vents and doesnt blow up but its definitely broken after that.