Scientists have mapped out what they think could be a deadly exclusion zone if one of the world's most famous volcanoes, Mount Vesuvius, erupts again.
Vesuvius is close to the city of Naples, which has an estimated population of just over three million. A major eruption could cause widespread panic and a mass evacuation, according to the experts.
A number of studies and simulations have been mapped out, including one in 2007 that suggests over 300,000 people could be killed if they are not evacuated in time.
