There are some excellent ideas in the threads above. It's been awhile since I've been in management but...
Some years ago we lost the father of the owner of the store we worked in (and I basically managed). Mr. Hogan was a great guy and while he could be a pain in the butt to his son he was always great with the rest of us. He'd come in to fill in on peak days and help watch customers and the like. I liked him and he always had a kind word.
When he passed away (also from cardiac issues although he was older and retired he still wasn't THAT old) we made time for those who had worked with him to attend the funeral. We also couldn't close the store.
What I did was take each person I could aside and have a chat with them. I reminded them that Mr. Hogan wouldn't have wanted his son's business hurt because of him. I empathized and we shared a few minutes of grief and then got back to it.
That doesn't sound like much - but a little thing showing that a manager cares can go a long, long way. I also made sure I was more available than usual to pitch in where and when I could on the floor if someone needed a break. Most didn't - but there were one or two occasions.
Naturally we were a small op with only around ten employees so it was easier - and the funeral was in the afternoon when a few of us could get free with the others to cover.
I'm sure you've likely thought of all of the above - and probably done it as well. I just wanted to pass on that it can (and did) work for us.
Good luck. It's a very sad thing. I hope everyone will be okay. I'm positive you'll do fine.
Just don't stick anyone with a spear <wink>
Silver Warder
Warder to Rebelaessedai
Risk everything - or gain nothing.
Geoffrey de Charney - 1356
Deeds - Not words
Remembering Joe (CrazedWeasel)