Conn. Gen. Stat. § 28-21

Any person owning or controlling real estate or other premises, together with his successors in interest, if any, who voluntarily and without compensation grants to the state or any municipality a license or privilege, or otherwise permits the designation or use of the whole or any part of such real estate or premises, for the purpose of sheltering persons during an actual, impending, mock or practice attack or other disaster shall not be civilly liable for negligently causing the death of, or injury to, any person using such real estate or premises for the purpose of shelter during such an attack, or for loss of, or damage to, the property of such person.