Dear sir/madam
I am writing this letter to inform that I will be unavailable to attend charity event because of unfortunate circumstances.
I am feeling ashamed to not being in the upcoming charity event. I know it is very wrong to tell you about the sudden change in plan, as it will be hard for you to arrange a new volunteer at a moment.
Actually, my sister fell from stairs and she got some serious injuries. That’s why I have to go to get her to the hospital for the treatment. There is nobody else here who can take care of her, so I have to be with her until she get better.
I have an exclusive idea to help the charity without being in the event. I will share the pamphlet of our charity on my social media accounts. It will support the charity to raise found without needing to join the event.
Hope you will forgive me and give importance to my suggestion.
Your faithful,
Inderjit
