Those who remained in Darwin faced the threat of several diseases due to much of the city being without water, electricity or basic sanitation. An initial response was to vaccinate residents for typhoid and cholera. Approximately 30,000 people were homeless and were forced to seek shelter in several makeshift housing and emergency centres that lacked proper hygienic conditions. Volunteers came in from across the country to assist with the emergency relief efforts. Trench latrines were dug; water supplies delivered by tankers, and mass immunisation programs begun. The army was given the task of searching houses for bodies of people and animals, as well as locating other health risks; for example, cleaning out rotting contents from fridges and freezers across the city. This was completed within a week. Houses which had been 'searched and cleared' had S&C painted on an external wall. The city itself was sprayed with malathion to control mosquitoes and other similar pests.