My B. albo died. Can someone tell me why?

[Yuzan]

I found my B. Albo dead with a white sticky stuff on her abdomen. Was it ruptured? Substrate was okay since I watered them regularly but it was watering day today and when I checked substrate was a little dry. I don’t know the cause and I want to know what might be the cause this time to prevent it from happening to my other Ts.

 

[Yuzan]

More pictures. Ruptured abdomen?

 

[Theneil]

What are you using for substrate. Looks like it could be abrasive.

Please post pictures of enclosure for help. We can't really do much without knowing the whole scenario.

 

[Glorious Baboon]

Did you drill your air holes from the inside or outside of the container?

 

[FrDoc]

Hard to tell positively from that image, but my first thought is impaction.

 

[Nightstalker47]

Did you see a blockage near her anus? Very strange.

 

[Teal]

I found my B. Albo dead with a white sticky stuff on her abdomen. Was it ruptured? Substrate was okay since I watered them regularly but it was watering day today and when I checked substrate was a little dry. I don’t know the cause and I want to know what might be the cause this time to prevent it from happening to my other Ts.

Their substrate should always be "a little dry." Slings can have part of the sub moistened for hydration, but they shouldn't be on wet sub.

How much height did the sling have from sub to enclosure lid?

 

[boina]

From the pics it is pretty hard to tell what happened to your sling, but like @Teal I find your watering practice pretty worrying. You are aware that too much water kills as surely as too little?