How does Millie break the news of Clarisse's death to Montag?

Millie is quite matter of fact when speaking about Clarisse's death. When Montag questions her about Clarisse, who he has not seen in days, Mildred says she had forgotten to tell him that Clarisse was struck by a car and killed four days earlier, and that her family has since moved away. Montag is very upset to hear this news and can't believe Millie forgot to tell him.