How do I tell my kids that our dog is dead?

[TinyEvel]

It's been a rough 12 hours.

last night our dog Josie (small Shepard mix who's been in the family 11 years) was all of a sudden extremely catatonic and panting on her side. Her head was twitching and eyes shut. We took her to the animal emergency room around midnight and admitted her. Diagnosis was that she was bleeding in her eyes and gums and her blood had only 1 percent the platelets it should have.

Without the ability to clot, she had developed internal bleeding. There was blood filling her head and causing neurological damage form pressure on her brain. Today it got worse and we made a tough, difficult decision to euthanize her.

24 hours ago she was 100 percent normal.
This has come so sudden and so difficultly. Our kids are 8 and 9 and we haven't told them. They don't even know we took her to the hospital yet, but they saw her sick last night.

I'm sure some of you have gone through pet loss with kids. Just looking for some tips. We're supposed to go get a Christmas tree tonight after school. Do I tell them first? afterward? I cannot believe we'll be able to do it without us crying. my wife for sure.