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 last census, in the mid-1990s, estimated that there were only 16,900 of the animals left in the wild, but following more than a decade of habitat destruction and fragmentation and years of civil unrest, the eastern lowland gorillaâs population may have declined by half or more.