Cranes and heavy equipment sit at the construction site for the third sets of locks on the Pacific side of the Panama Canal near Panama City, Panama, on Thursday, April 24, 2014. Panama&#39;s presidential contenders are winding down their campaigns ahead of the May 4 election as a strike by construction workers paralyzes the expansion of the country&#39;s signature waterway, its biggest economic resource. Photographer: Susana Gonzalez/Bloomberg via Getty Images