This morning I groggily ignored a call and inadvertently destroyed a girl.
Wow, are you serious? Why weren't you able to answer her call?
I was barely awake and late for work, so I didn't notice it.
You should contact this girl and make amends for missing her call. Explain your side of it and try to let her know how you didn't mean to ignore her.
I'm afraid that she won't feel any better even if I tell her.
I think if you apologize and explain why you didn't answer the phone then she'll understand and won't feel so bad. There's no harm in telling her that you're sorry.