 The former Washburn "A" Mill building on the west side of the falls exploded on May 2, 1878, but its owners quickly rebuilt the west side district, including a new, larger Washburn "A" Mill.Meanwhile, in 1880, Pillsbury began building the huge Pillsbury "A" Mill on the east side of the falls.It had a capacity of 4,000 barrels per day when it first opened.