An American cargo ship was attacked by pirates armed with grenade launchers and automatic weapons in the Gulf of Aden on Tuesday, but the attackers failed to take over the ship, which was able to continue with its delivery of food aid to the Kenyan port of Mombasa. The ship, the Liberty Sun, was damaged in the attack but the crew members were not hurt, according to a statement from the ship’s owner, Liberty Maritime, of Lake Success, N.Y. “We are under attack by pirates, we are being hit by rockets. Also bullets,” a crew member aboard the Liberty Sun,...