Possible honeybee colony on my patio suddenly dying

I just moved in about a month ago, no bees in sight. After hurricane Irma we had some damage to one of our wood pillars on our patio. I saw a swarm of what I thought were hornets, a few got into the house and upon further inspection they appear to be honey bees. The swarm grew very rapidly and about 3 days ago I would estimated the amount of bees to be around 1,000. Tonight I went out into my porch and there are about 100 dead bees all over the patio. Does anyone know why this would happen? I would hate to see more die.

I suspect the bees where in the house before you , often homes have bees and no one notices . The storm damage might have made the nest uninhabitable and the bees have now left having found a new home .