I lost seven plates in my kiln this week for the first time!!

[Michelle Moyses]

Hello folks! I am a porcelain painter in Brazil! I work with china paint for 25 years... This week I lost seven plates in my kiln. Six at a time (Second firing)  and another one in  another time (fist firing) ...   have lost some, rarely, very uncomon one piece or 2 but at this time I am very anxious because is the There have been losses of dishes a few times but so this is the first time ...
I'm scared because it's a big order, the biggest one I've ever taken and this has never happened to me ...
What could have been?
Exaggerated load of the oven? I've done other burns like this and there's never been a problem ...
Concentration of the pieces arranged in the same way in the oven?
They were on separate shelves ... two on each shelf. Some broke that one that was in front and the others in the background.
I changed the batch and then burned the other dishes without shelves and with less load and yet lost one more.
I do not use level ... I burn straight as I have always done my whole life and I never had problems ....
Can anyone give me a hint of what might be going on?
Today I'm doing another burn and I used it this time ... but I'm scared to death ...

The photo of the bad firing is bellow! 
Thank you if anyone has the knowledge to help me ... 

[neilestrick]

Why are they upside down? Are you buying finished glazed plates and doing the china painting on them? Can you post a picture of the broken pieces, how they cracked, etc?

[Mark C.]

I'm unclear on why the plates are upside down?They should be fired on their feet rightsize up.Also are you firing them to fast or cooling to fast?

A kiln load of plates should be slow fired and slow cooled. These look like prefinished bought plates?