I agree that he could have at least replied with some sort of support. I'm sorry he hasn't responded yet.

I wonder if he had something happen that is making him late to respond back to you. I hope he cares and was tied up with something unexpectedly. He could be working with someone else that is having a crisis or he is having a crisis himself. I was on a call for work recently and my coworker dropped from the call unexpectedly and it made me annoyed. I found out a few hours later that he had a fire in the house.