The single deadliest tornado to hit the US in 60 years will cost insurers $1bn to $3bn, according to intial loss estimates from cat modelling firm EQECAT.

The tornado, with winds up to 198mph, struck Joplin, Missouri on Sunday, killing at least 116 people and injuring thousands.

EQECAT said despite only being midway through the 2011 tornado season, aggregate losses have reached an "extreme level".

The EF4 tornado initially touched down at the Kansas-Missouri state line just southwest of Joplin and tracked east-northeast through residential/commercial areas of southwest Joplin proper.

The tornado intensified as it tracked across Joplin, moving just south of the downtown area. The town suffered catastrophic damage as the tornado destroyed several schools, downtown businesses, and St. John’s Regional Medical Center.

Preliminary reports from emergency management officials in Joplin indicate that up to a quarter of the building stock (2,000 buildings) in the city have been destroyed.

It is estimated that 5,000-10,000 buildings/houses (50-75%) have been damaged by the tornado’s wind field.