I've fried two so far.
While I briefly tested the first with 9v and 12v, it died after a few minutes of operation from USB.
I added the 1.5k resistor before the relay IN when I built the project a second time.
I completely rebuilt the project with new wire, solder, terminal blocks, relay module, etc in an effort to rule out a short due to construction fault.
The second Nano was powered exclusively via USB and also ran for a few minutes continuously before freezing up.
The data sheet for the relay module says it draws 65mA in operation. As you can see from my diagram, it is powered by the 5v rail. The 5v rail still outputs 5v after the controller dies and thus the relay still ticks being active low. The D2 pin outputs 2v as soon as the nano is powered and doesn't change.