You can try getting a tap kit and tapping it then running a threaded plastic nipple off it. That maybe more trouble than it’s worth as your radiator is anywhere from $60+ online and it’s straight forward to remove / not buried in there. Would probably take you an hour to replace it or less.

It didn’t just explode spontaneously like that, probably what happened was when they hit the curb, they managed to nick the tire enough to gash it, but not completely cut into the tire. Then hit a pothole hard enough would cause that area to pop like that or some combination along those lines.