New York City ? The last of seven bodies was pulled from the rubble Monday at the site of a crane collapse that obliterated a town house and severely damaged other buildings.

Six construction workers and a woman in town for St. Patrick’s Day were killed Saturday when the crane broke away from an apartment tower under construction and toppled like a tree onto buildings as far as a block away. The last three bodies were found Monday.

A preliminary city investigation found that the 19-story crane toppled after a steel collar used to tie it to the side of the building fell as workers attempted to install it.

When the equipment fell it damaged a lower steel collar that was a major anchor securing the tower crane. Investigators say that with the elimination of the lower support the counter-weights at the top of the crane’s tower caused it to fall.