in AD 79 buried Herculaneum under approximately of ash. It lay hidden and largely intact until discoveries from wells and tunnels became gradually more widely known, notably following the Prince d'Elbeuf's explorations in the early 18th century. Excavations continued sporadically up to the present and today many streets and buildings are visible, although over 75% of the town remains buried. Today, the Italian towns of Ercolano and Portici lie above Herculaneum. Ercolano was called Resina until 1969 when the modern name was adopted in honour of the old city. Eruption of 79 AD The course and timeline of the eruption can be reconstructed based on archaeological excavations and two letters from Pliny the Younger to the Roman historian Tacitus. At around 1:00 pm on the first day of eruption, Mount Vesuvius began spewing volcanic material thousands of metres into the sky. When it reached a height of , the top of the column flattened, prompting Pliny to describe it to Tacitus as a stone pine tree. The prevailing winds at the time blew toward the southeast, causing the volcanic material to fall primarily on the city of Pompeii and the surrounding area. Since Herculaneum lay west of Vesuvius, it was only mildly affected by the first phase of the eruption. While roofs in Pompeii collapsed under the weight of falling debris, only a few centimetres of ash fell on Herculaneum, causing little damage; nevertheless, the ash prompted most inhabitants to flee. At 1:00 am the next day, the eruptive column, which had risen into the stratosphere, collapsed onto Vesuvius and its flanks. The first pyroclastic surge, formed by a mixture of ash and hot gases, flowed down the mountain and through the mostly-evacuated town of Herculaneum at . A succession of six flows and surges buried the city's buildings to approximately 20 m depth, causing little damage in some areas and preserving structures, objects and victims almost intact. However, other areas were damaged significantly, knocking down walls, tearing away columns and other large objects; a marble statue of Marcus Nonius Balbus near the baths was blown 15m away and a carbonised skeleton was found lifted 2.5m above ground level in the garden of the House of the Relief of Telephus. The date of the eruption has been shown to be on or after 17 October. Support for an October/November eruption has long been known in several respects: buried people in