2 dead Fire Belly Toads...Why, what have I done!?

[ctroxtell]

1----what 'kind' of frog is it ( what species)
Bombina orientalis
2----please include a photo of the frog

3----Please include a photo of the frog's current enclosure
EDITED: Just got everything back in order in the enclosure. Note: screen lid not shown it picture but it is installed
Enclosure is currently in disarray from just being moved back home till we understand what is happening.
4----size of enclosure ( W" x D" x H" )
12" x 12"x 18"
5----# of inhabitants - ( if there is another frog --- is there a size difference ? )
Only 1
6----has or was the frog kept with a different species or with any other tank mate
Has had 2 other buddies, 1st died then we brought another in and it died over the weekend, both died roughly about 2 weeks after being introduced
7----is there a new tank mate----was the new tank mate quarantined
None of my wife's toad's were quarantined, they were purchased and just introduced into the tank
8----what is the typical humidity level
Not 100% sure, but had a filter pump running constantly to keep air humid in tank and help clean the water
9----what temperature is maintained
Temp. was around 75 degree's F
10---what is, specifically, being used to maintain the temperature of the enclosure
Nothing other than room temperature
11---describe the enclosure lighting ( very specifically)
Natural lighting through large window
12---describe enclosure maintenance ( water changes, cleaning etc)
Water was changed out about 4 weeks ago upon moving the frogs to classroom
13---what kind of water is used
Tap water mixed with Tetra's AquaSafe
14---material(s) used for substrate - be very specific
None at the moment
15---enclosure set up:
Filter pump normally sat in back right corner, had most the gravel pushed to the left side for a land and water on the right so the frog could swim. Used a hanging plastic vine to quieten down the water so as to try not to stress the frogs out, and a rather large piece of bark for the frogs to hide behind or climb on. Has a background of a rain forest on the back side.
16---when is the last time the frog ate
Yesterday
17---have you found poop lately
I think so, don't think I knew what it was at the moment though
18---how often is the frog fed
About every other day
19---what size feeder is given
Small crickets
20---what other feeders are used as treats
Occasional meal worms
21---what is the frog's main food source
Crickets
22---do feeders roam free in the enclosure or is the frog bowl fed
Roam free
23---vitamins - what brand and how often
None
24---calcium - what brand and how often
Crickets are gut loaded with Flukers Orange
25---was the frog without calcium for any period of time
Not that I am aware of
26---approximate age of the frog
Very young I would guess
27---how long have you owned the frog
Only one still alive has been with us for about two months, other 2 died 2 weeks after acquiring them
28---who cared for the frog before you
Petco
29---is the frog wild caught or captive bred
I'm guessing wild caught from what I've read about pet stores
30---how often the frog is handled -- are gloves used ( what kind of gloves)
Very rarely, none
31---is the enclosure kept in a high or low traffic area
Kept in a 4th grade classroom against an outside wall by the windows
30---has or was the frog properly quarantined (yes or no)
-----for how long
No, had no clue about quarantining
32---has the frog been treated with any medication:
No.

Thank you again, any advice is greatly appreciated. My wife's students loved having the frogs in the classroom.

[ctroxtell]

Any ideas?