You could try the a local coin store/precious metals store. If you try to get rid of it FAST, there is a good chance you will not get the price as if you were to look around. Good luck if this is not hypothetical.
If the situation is dire, a pawn shop or cash for gold place, but you'd be lucky to get 50% melt Sent from my DROIDX using Tapatalk
Many jewelry stores buy Silver and Gold. Those the make their own jewelry are the best bet, although some of the chain stores will buy as well. Normally you can call them, and coin shops, for a current price before making the trip.
Call all your local coin shops and ask around. There is one in my area that beats all others in what they will pay as well as how low they will sell. You might be surprised. I would include the "Sell us your gold!" places as well. There are a lot of those around, but I doubt they're consistently reputable.
In addition to the suggestions other people talked about like dealers, pawn shops, etc, I also recommend one obvious one: Collectors and investors like us. If you approached me, for example, and said "Here's 100 oz, I'll sell them to you at X% below melt" you would have the money in your account in seconds. Many of us here collect silver and may not need the money as fast as you, so if a collector can get a good deal they will probably be the source that would give you the most money for your silver.