When a disaster overwhelms the ability of state, local, and voluntary agencies to adequately provide essential services on their own, the federal government generally plays a central role in disaster response, providing selected resources where they are needed. The federal government has provided significant funds for transit services following past catastrophic disasters. For example, about $4.7 billion was provided in emergency supplemental appropriations for emergency transit services in response to the September 11, 2001, attacks and $232 million in response to the 2005 Gulf Coast hurricanes.