A man camping in the Boundary Waters Canoe Area Wilderness in northeastern Minnesota died Sunday night when a tree fell on him as he sought shelter from a powerful storm that rolled through the area, the Cook County Sheriff's Office said.

Craig Anthony Walz, 43, of Rochester was with his son and another man and his son near Duncan Lake, about 30 miles north of Grand Marais, when the storms with high winds and heavy rain toppled a mature white pine, which hit Walz.

Rescuers responded to the call, which came in at 10:27 p.m., said Sheriff Pat Eliasen.

Walz is the brother of U.S. Rep. Tim Walz, D-Minn. Sara Severs, a spokeswoman for the congressman, said the family "wants to express their profound gratitude to law enforcement, first responders and fellow campers who responded immediately to help.

"The family is also grateful for the messages of support and prayers they have received," her statement continued. "They are devastated by the loss and ask for privacy at this time."

Walz's son, Jacob, also was hit by the tree. He suffered severe injuries and was taken by helicopter to Essentia Health-St. Mary's Medical Center in Duluth. The hospital said Monday night that it was not releasing any information about his condition.

Craig Walz was a math and science teacher at St. Charles High School in southeastern Minnesota, according to a statement from Ken Martin, Minnesota DFL Party chairman. Walz "is remembered by his family, students and community as an amazing husband and father, and outstanding teacher, a passionate mentor and loving friend," the statement said.

In a Facebook post, Shellie Henry, a former student of Walz' at St. Charles High, praised him for all he did for her and other students. "Thank you for always greeting everyone with a smile. You were one of the best. You will be missed, Mr. Walz. Rest in peace."

A second call for help came Sunday night from a man who was hit by a falling tree near Clove Lake on the U.S.-Canadian border. He suffered injuries to his upper body and was hospitalized.

Also on Sunday night, St. Louis County authorities said two adults and six young people in an Outward Bound group were injured in an indirect lightning strike in Sunday Bay at Crooked Lake when lightning hit the trees near where they were standing. They were taken to Ely Bloomenson Community Hospital; the injuries did not appear to be life-threatening, officials said.