If you hit $0 Avail. funds for trading, your account will go into a margin call and Ameritrade will force you to sell positions or deposit money. I'm going to assume your Account Balance isn't -8.1k because you would have hit a margin call long before your account went negative unless this all happened overnight.
Sadly, these peaceful animals may not survive into the next century. Ape conservationists say time is running out, as there are only about 720 mountain gorillas left in the world, and the majority of gorilla populations are plummeting.
There are the Eastern Lowland gorillas and the Western Lowland gorilla. The Mountain gorillas have very low numbers and then there are the Cross River gorillas. All of these types of gorillas are considered to be endangered due to low numbers, destruction of their habitat, and poaching.