In Connecticut, and I would imagine in most states, upon the approach of an emergency vehicle you are required to move to the right side of the road, clear of any intersections, as close to the curb as practicable, and stop.
If you are stopped at a traffic light you should, if possible, move to the right side of the road and stop. If that means you have to make a right turn even though you intended to go straight, so be it. You are required to clear the road in a safe manner.
Of course, if you are blocked in by other cars also stopped at the light, and you can't move, then obviously you are not required to.
Cogito ergo summopere periculosus.
Fiat justitia, ruat coelum.