What's the worst that can happen from too much sleep deprivation? Can you die?
The short answer is: Yes.

Fatal familial insomnia is a genetically passed down disease that at some random point in a carriers life will suddenly stop them from sleeping, ever, they die within 7 to 18 months 

I know you did not ask about the disease, but it shows (even without illegal war tests) that it will kill you eventually, even in humans. 

I believe in humans without the disease a complete lack of sleep may kill them within weeks, but who knows? maybe it was the drug.