According to this obituary, Marcus died on August 8. According to his sister's post he died of COVID. She admonished him in a post for believing COVID to be a "hoax".
Here he is in the ICU:
Here is his sister's post using his Facebook account after he died. I don't need to say anything else:
Thank you and well said, Michele!
RIP Marcus.
Oh hell Yes! It's about time a family member was more vocal about losing their loved one to Covid virus.
Way to go, Michele! I’m sorry that your brother and father made a stubborn and selfish choice, and left you in pain and grief. Never stop trying to convince others to protect themselves. I haven’t given up, and thankfully have a few success stories.
Marcus died on 8/8/21, Marcus' dad died of COVID on 9/3/21. No telling how many other people Marcus took out. Feeling sorry for the sister.
His sister is better off without Mark in her life. The world is better off without Mark in it.