They broke his heart! In trying to keep Paul from harm, his fellow followers failed him. All of us of little faith, we DON'T know how to protect ourselves against the world. Only God knows.

Acts 21:13
Then Paul answered, “What do you mean by weeping and breaking my heart? For I am ready not only to be bound, but also to die at Jerusalem for the name of the Lord Jesus.”

Bible Gateway link: Acts 21:13 (NKJV)