What happens when a flying sword is killed?

In 5e there’s a monster called a flying sword (small construct). When it is killed, what happens?

  • Does the sword break?
  • Does it lose its magic and revert to a mundane sword that a character could use as a weapon?
  • Does it disappear?
  • Does it become inactive for some period of time and eventually regain its magic to continue bothering adventurers?
  • Something else?