Burials underneath the church floor in Uvdal

In the Middle Ages, high-status individuals could be buried below the church floors. This custom was maintained in Norway up until 1805. The priest had automatic rights for such a burial while others had to pay a lot for such privileges. At Uvdal many humans have been found buried under the church floorboards, both with and without caskets. Who were these people and why were they chosen to be buried under the church floor? 

During the last half of the 14th century, two women and two girls were buried together under the church floor. The grave was placed at a central location in the church which normally would be reserved for high-status individuals. They were not placed in caskets, and nothing indicates that they were covered with soil. Large stones were later placed over the grave.

Who were they and how did they die? Such things are hard to answer, but we do know that he Black Plague ravaged Norway at that time, claiming multiple human lives. Could the grave be connected to such events?