Grinnell Mutual Reinsurance Co. celebrated the groundbreaking of a new state-of-the art new conference center Monday in Grinnell. The 33,130-square-foot facility, which will include a 250-seat auditorium, nine multi-purpose meeting rooms, a video conferencing room, dining services and reception areas, and will provide onsite training and event space for the company's employees and customers, the company said. Scheduled to open in May 2015, the conference center will adjoin Grinnell Mutual's existing headquarters at 4215 Highway 146 South. Neumann Brothers Inc. is the contractor for the facility, which was designed by DesignBuild Solutions, an in-house subsidiary of Neumann Brothers. Grinnell Mutual plans to make the facility available to the Grinnell community for local events.