Cynical/realist take: Take responsibility and then hope your bosses already love you, you can immediately both come with a way to prevent it from happening again, and convince them to give you the resources to implement it. Otherwise your responsibility is, unfortunately, just blood in the water for someone else to do all of that to protect the company against you and springboard their reputation on the descent of yours. There were already senior people scheming to take over your department from your bosses, now they have an excuse.