The flexplate is cracked.
This is a common failure on your vehicle. Typically this occurs because the torque converter bolts come loose, or if the transmission was ever removed and the bolts were not torqued properly this will happen. The only way to repair it would be to remove the transmission and replace it. You should enlist the assistance of a transmission shop so that they can also make sure that there are not any transmission problems that may have caused this.
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