Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

the tornado outbreak sequence of june 1966 was a series of tornado outbreaks which happened between june 2 and june 12.
tornado outbreak sequence of june 1966

the british rail class 931 was reserved for former southern region electrical multiple units converted for departmental use.
british rail class 931

gary breen (born 12 december 1973) is an irish football player.

gary breen

