The Sidoarjo mudflow (commonly known as Lumpur Lapindo, wherein lumpur is the Indonesian word for mud; and as Lusi is the result of an erupting mud volcano in the subdistrict of Porong, Sidoarjo, in East Java, Indonesia, that has been active since May 2006. It is the largest mud volcano in the world. Responsibility for the disaster was assigned to the blowout of a natural gas well drilled by Lapindo Brantas, although company officials contend it was caused by a very distant earthquake that occurred in a different province.