Surely the exchange where you have created an account is responsible for the loss of your coins. You should also share some amount of the problem as you should conduct a research beforehand since mostly bad exchanges have been hacked. You get your loss recovered if the hacked exchange is reputed and good.
That's not exchange's fault if only the amount from his wallet got stolen. Exchanges can be hacked but with coinbase, it has not happened so OP got hacked via malware installed on his device or his email account got compromised so hacker got the access to his wallet.