816
North Korea ' s military may have fired a laser at a U . S . helicopter in March , a U . S . official said Tuesday , as the communist state ditched its last legal obligation to keep itself free of nuclear weapons .
 attack: fired
Please tell me event type and its trigger word from given type options. Output format is "type: trigger".  Option: declare bankruptcy, transfer ownership, marry, die, phone write, arrest jail, convict, sue, transfer money, end organization, start organization, end position, merge organization, start position, transport, charge indict, elect, attack, injure, born, extradite, release parole, sentence, demonstrate, meet, trial hearing, divorce, nominate, fine, appeal, pardon, execute, acquit 
Text: {0} 
Answer:
 attack: fired