Can one package of chewing tobacco at once kill people?

Yes.

Sixty milligrams of nicotine (the amount in about 30-40 cigarettes [1]), has the potential to kill an adult who is not a smoker

Holding an average size dip or chew in your mouth for 30 minutes gives you as much nicotine as smoking four cigarettes

on the average, one can of chew/chaw contains as much nicotine as 60 cigarettes. Apparently the average user receives between 130-250 mg nicotine per day. Again, on average, one "dose" of chew contains 14.5 mg of nicotine (while the average cigarette has 8.5mg)...