ご苦労様[gokurousama] thank you very much for your ...
御苦労さん[gokurousan] I appreciate your efforts
慰労[irou] recognition of services
過労[karou] overwork
過労死[karoushi] death from overwork and mental stress

気苦労[kigurou] worry
漁労[gyorou] fishing
共労者[kyourousha] coworker
勤労[kinrou] labor
勤労階級[kinroukaikyuu] salaried class

火災[kasai] conflagration
火災保険[kasaihoken] fire insurance
核災害[kakusaigai] nuclear disaster
公務災害[koumusaigai] accidents in line of duty
災い[wazawai] calamity

災禍[saika] accident
災害[saigai] calamity
災難[sainan] calamity
災難に遭う[sainanniau] to meet with misfortune
災厄[saiyaku] calamity