MINNEAPOLIS — Construction on the new Minnesota Vikings stadium is more than 30 percent completed.

President Mark Wilf was among team officials and employees who visited the site Friday to serve lunch to workers in gratitude for their effort.

The Vikings sponsored the tailgate-style meal of burgers, baked beans and chips for up to 1,000 people in a heated area of the building. Workers ate in shifts to accommodate the crowd. They were given thank-you cards and sweatshirts commemorating project.

The current size of the crew is about 750 people. Mortensen senior vice president John Wood said they're "some of the most hard-working and productive construction workers anywhere in the United States."

The concrete work is roughly 60 percent completed. The $1 billion stadium is set to open in August 2016.