Bitcoin is the mothership, if it collapses all the others will have a very hard time. They are all Bitcoin forks.
if anything were to crack, like maybe because of the advent of quantum computers, I suspect the first thing to crack is the private key in the wallet, since a powerfull enough quantum computer with enough Qbits could crack the privates keyes using Shor's algorithm.
All the wallets use the exact same public/private key system, so all the coins would be at risk IMHO