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.
The western lowland gorilla estimated population is about 94,500 whereas river side gorillas are Africas most endangered great apes; there are only 200 river side gorillas left. The population size of eastern mountain gorillas is 700 and of eastern lowland gorillas is estimated to be between 2000-16,900.