Anyone else losing birds in this weather

So I have only just gotten back from holidays and went into see my young stock ( hatched May) from performance and watered them the night I got back they had food and all was well in the coop. Mind it was hot they had the poop door open and the windows and there was 4 dead by the door in the morning. I guessed crushed.
Then last night we had a big rain and I had cleaned out the coop and put down fresh bedding , never used wood shavings for them before only straw and so the new bedding was scary for them .............the rain was coming and not one would come into the coop so I tried to put a few in to get them going in . Well when the rain came down hard I made a run for it myself and hoped they would go in. Well this morning I check on them and 2 dead in the corner, crushing again. My numbers are falling and it's not like I have too many in there. I am guessing it is a mixture of heat being a problem and the weather with thunder storms. There was lighning and thunder as well last night.
So please is anyone else having problems , these birds were hatched early May so around 12 weeks old.
Oh and what to do to stop it from happening as I am not mother nature and can not control the weather. I have put up a fan now so hopefully it will help.
My other coop with my adult birds is just fine even with the same temps.
Thanks all

I lost 67 chicks during a major storm when they were younger, mostly meaties but there were some others as well. All I could do was cry and put the carcasses into bags. They all piled in the corner, I am sure they were scared so they piled on each other.

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Chicks, not too smart, I could have lost about 15 little ones, which are 2 months old. They are growing in a separate area from the adults, but adjacent to them. Each night at dusk I herd these little ones into their house. always have. Last night, we were out until about an hour after dark. Not like me to not close up before the darkness falls, but sometimes I am lax, not often as such, but now and then that is the way the cards fly. We came home to close down the chickens, and not one of these dummies was in their house. They were all huddled outside in a corner, right near the entrance pop door to their home. go figure. It bothers me, as I have not had this happen before and really have no clue why. They know where home is, to be safe and sound. So, they were prime target, should anything wanted a mouthful of babies and fluff, cause that's all they are. I am letting two brooding buff orpingtons into their pen today with their babies. perhaps those mammas will take these older ones below their wing and take them inside when the creepy nighttime comes. I need to do a little test with this tonight and see if they just needed some extra mothering, sigh. tonight will tell that tale. Hope that no one loses any more youngsters to silly youngster antics. To that, have a beautiful day, CynthiaM.