Burmese passed away

Question
Hi there. I wanted to see what you think about a situation
that happened at our animal shelter tonight. We do have a
vet. He was not in the office when this happened and by the
time i was able to reach him, the burm had already passed.
We have a 11 foot female burm, medussa, who has been at our
rescue for 9 months. She is fantastic. great attitutde,
great eater, very healthy. We had her out interacting with
her today like normal and all of a sudden she started
throwing herself around uncontrollably and then went limp.
She passed away completely about 30 minutes later. I noticed
that the lining around her mouth (outside) was a bit purple.
there was no discharge or other signs of issues. Nothing new
in her diet...same supplier, no change in enclosure and no
recent mite issue, etc. Possible stroke? anuerism? seizure?
I will of course talk to the vet again tomorrow but we are
all so broke up. We have been running our animal shelter for
2 1/2 years and we don't confess to know everything about
everyone...but we were quite attached to her. :( Any
information or insight you could provide would be
appreciated. Robin

Answer
I've seen similar behavior a few times.  NO idea what causes it, but your guesses are about the same as mine would be. The vet might be able to tell during a necropsy.  I once had a boa turn around, bite itself in the back (about where it's heart would be), and then roll over dead, all with me standing there going "wth!"  My guess there was heart attack.  Sorry for your loss, B