 Four months later , in May 2005 , a second spike had to be cut off by firefighters after it was discovered hanging loose . At that time the sculpture was closed off to the public , and the junction and pathway near the sculpture were temporarily closed . As a result , some of the joints were re @-@ welded , with equipment put in place to prevent excessive movement . This consisted of retrofitting tip weights to 70 % of the spikes ' weights . 
