Because of the devastating impact of hurricane Sandy, many people were asked to stay home and some states in the US had to impose curfew to have a control on the situation. Most places in the US were out of traffic and had no street lights. To enable the police to have a control on the present situation, they imposed curfew.
The government of US had to enforce curfews in many cities, so that people are safe and protected in their homes. Enforcing curfew will deter people to come outdoors and not be seen on the streets and roads during the dreadful hurricane Sandy. It is for their own safety that the government had to take this kind of measure.
The police had to impose curfew to make people stay off the roads and deter looting. During emergency calls, the police was unable to get to those who needed help because the roads were crowded causing heavy traffic obstacle and the police were unable to rescue the hapless victims.
The impact of hurricane Sandy has left 8.1 million people without electricity, dozens of people lost their lives, nearly 18,000 flights were canceled, about 80 to 100 homes were destroyed, thousands of people were evacuated, schools and offices were closed, many people waiting in long queues at gas station for fuels and also the hurricane sandy had its impact on the economy of US.
Sandy was one of the biggest storms that hit US. Its been a decade since US faced any such problem related to natural disasters. Major problem that confronted the citizens of US due to sandy storm was the outage of power. Nearly 8.2 billion homes and businesses were left without power, leaving thousands of people in the dark. 
Hospitals faced severe problems due to the outage; especially new born babies that were in the intensive care unit, doctors and nurses had to give the new born babies battery operated respirators for breathing.