USB thumbdrive plugged into Macbook Pro which instantly goes black, bricked?
Either your USB thumb drive is broken, or the specific USB port on your MBP is.

The easiest way to test is for you to plug another USB device to the same USB port, then 


Locate the Apple logo on the top left corner of your display, and click on "About This Mac"
A window will appear. Click on the "More Info…" button
If you're running OS X 10.6 Snow Leopard, skip to the next step. If you're running OS X 10.7 Lion, another window will appear on which you'll have to locate and click on the "System Report" button. 
A new window will appear, on the left column, locate "USB" which is listed alphabetically under "Hardware". The details of the USB device you connected to that USB port should be displayed. If it is, then your USB port is working normally, which means your USB thumb drive is the problem.