It happened at the range this morning, the lower half of the trigger came off. I didn't mess with it at the range, just packed up and came home. I looked at how my M&P45 had it in there and re-inserted the lower part and pressed the pin back in, it releases the striker so I guess it's in there correctly.
I've probably got 7k rounds through this gun. Is this just something that needs to be checked on M&Ps, or is there a fix or replacement part?