A PACK, NOT A HERD: “A tour bus of US senior citizens defended themselves against a group of alleged muggers, sending two of them fleeing and killing a third in the Atlantic coast city of Limon, Costa Rica police said on Thursday. One of the tourists – a retired member of the US military – put assailant Warner Segura in a head lock and broke his clavicle after the 20-year-old and two other men armed with a knife and gun held up their tour bus Wednesday, said Luis Hernandez, the police chief of Limon, 130 kilometers (80 miles) east of San Jose. “