The Battle of Quincy - Disable the bomb stuck

[RobinE]

I have entered the super-duper mart and spoke to the institute ambassador. The quest in the pipboy displays "Fight!".
I have taken out all hostiles but the quest doesn't seem to advance.
I have tried clicking on the bomb and it is currently inaccessible.
I have picked up all the security keys off the gunners.
Any ideas?

 

[RobinE]

Nevermind, I'm an idiot. I figured it out.