ROCHESTER — Crews broke ground Thursday on a four-story, 90,000-square-foot building heralded as the first step toward the creation of “Discovery Square,” a life sciences and biotechnology hub where Mayo Clinic doctors and researchers will collaborate with private firms to create new medical technology.

The 16-block “Discovery Square” district is one of six within Mayo’s $5.6 billion Destination Medical Center plan. Construction of the Mortenson building project is scheduled to be completed in 2019.