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.
Mountain gorillas have been isolated from eastern lowland gorillas for about 400,000 years and these two taxa separated from their western counterparts approximately 2 million years ago. There has been considerable and as yet unresolved debate over the classification of mountain gorillas.