Montgomery B. Case, chief construction engineer, began construction on the Hudson River bridge began on September 21, 1927, with groundbreaking ceremonies held at the sites of both future suspension towers. Each tower was to have a base with a perimeter measuring , and descending 80 feet into the riverbed. The riverbed around the towers' sites was dredged first, and then steel pilings were placed in the riverbed to create a watertight cofferdam. The cofferdams for the bridge were the largest ever built at the time. In early October of that year, the Port Authority received bids for the construction of the bridge deck. There were two main methods being considered for the span's construction: the cheaper "wire-cable" method and the more expensive "eyebar" method. The wire-cable method, where the vertical suspender wires are attached directly to the main cables and the deck directly, would require a stiffening truss to support the deck. The eyebar method, where the suspender wires are attached to a chain of eyebars (metal bars with holes in them), would be self-supporting. Ultimately, the Port Authority chose the wire-cable design because of costs, and it awarded the contract for constructing the deck to John A. Roebling Sons' Company. The corresponding contract for manufacturing the steel was awarded to the . The first serious accident during the bridge's construction occurred in December 1927, when three men drowned while working in a caisson on the New Jersey side.