Just after 1 p.m. on February 17, 2014, one week after demolition of the stadium bowl had begun, demolition crews were working on taking down the concrete ring beam that encircled to top of the Metrodome, when a portion of the ring beam collapsed out of sequence, bringing an immediate halt to the work. No one was hurt and no equipment was damaged by the collapse. After five days of investigation from structural and demolition experts, it was decided that the remaining portion of the concrete ring beam would be destroyed using controlled explosive charges—virtually the same method that was used to bring down the Metrodome's steel support cables for the roof. This second controlled explosion was a continued deviation from the original plan to not use explosives to destroy the stadium. As it was determined that this was the safest way to bring down the remaining ring beam structure. On February 23, 2014, the remaining ring beam and corners of the Metrodome were brought down with 84 explosive charges of dynamite. This enabled demolition crews to continue with the wrecking ball demolition method that was originally chosen (though the order in which the sections would be brought down were changed as a result of the ring beam implosion), to bring down what was left of the Metrodome. Despite this unexpected setback, Mortenson Construction said that the demolition of the Metrodome and construction of U.S. Bank Stadium were both still on schedule.