Police make second arrest in connection to London subway bombing

UPDATE: London police say a second man has been arrested in connection with the London subway attack.London police say a second man has been arrested in connection with the London subway attack.Police said Sunday that a 21-year-old man was arrested late Saturday night in Hounslow in west London. He was arrested under the Terrorism Act.Two men are now in custody for possible role in the attack that injured 29 people.Britain's terror threat level remains at "critical" -the highest level - meaning