The would-be suicide bomber who detonated an explosive device underground near the bustling Port Authority Bus Terminal is a former New York City cab driver who told investigators he carried out the attack for revenge, law enforcement sources said. Akayed Ullah, 27, who is believed to be from Bangladesh and was living in Brooklyn, told authorities in sum and substance from his hospital bed: “They’ve been bombing in my country and I wanted to do damage here,” sources said.