A specialized military unit designed to respond quickly to nuclear, chemical, biological or other catastrophes in the U.S. will be activated Wednesday.

The 4,700-person force is trained for search and rescue, decontamination, medical care, aviation, communications and logistics.

It's called a Consequence Management Force and includes personnel from the Army, Navy, Air Force and Marines.

Two similar units are scheduled to start up in the next two years. All will report to the U.S. Northern Command, the military command responsible for homeland defense, at Peterson Air Force Base, Colo.

The core unit of the first team is the Army's 1st Brigade Combat Team, 3rd Infantry Division at Fort Stewart, Georgia.