Usually, when a natural disaster strikes, then the first to respond is the emergency services who will be allocated the areas most in need, and then to those areas that are higher priority. This usually involves bringing in emergency services from other towns and areas, even from other countries when the disaster is of a larger scale.
At this point, charities also get involved and have volunteers flying in from all over the world either to help with the rescue efforts, bring aid and supplies to those who are involved in the disaster or simply to help offer support to those affected.
The emergency services will be at the scene until they have rescued all the survivors or simply for as long as they are needed.
Natural disasters are events that bring some of the wealthier countries together in order to help the country or countries in need. In the last Japanese earthquake and tsunami many different countries from all over the world contributed to helping the victims of the disaster such as the US, UK, China, France, Germany, Sri Lanka and many more countries. This shows the effect that a natural disaster has not only to the country directly affected but the whole world and the reaction to these disasters.