Near collision at BOS?

Does anybody have the details? From what I've heard on the news,
intersecting runways were in use and planes were cleared for takeoff on
both. A copilot on one saw the other and made his plane hop off a bit
early, narrowly avoiding the other.

Two controllers were sent back to get re certified before they and
operate again.

How does that work, anyway. Does one of the controllers just shout,
"I've got the intersection!" or is there an electronic means to claim
control of it?