LR circuit analysis

1. The problem statement, all variables and given/known data
Switch S is closed for long time in the figure shown. Find the current i as soon as the switch is opened.

3. The attempt at a solution

At t=∞ inductor behaves as closed circuit. So, I can simply replace it with a wire and calculate the current which comes out to be 9A. But I can’t understand what will happen when the switch is opened. Will the current die out instantly? Will it be the same as before?

Attached Images
File Type: jpg 20140422_220614.jpg (55.7 KB)

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