Gov. Tim Walz on Thursday called on the National Guard to bolster the search for two missing paddlers in the Boundary Waters Canoe Area Wilderness, recalling his own connection to random tragedy in the popular northeastern Minnesota camping destination.

St. Louis County Sheriff's Cmdr. Nate Skelton said earlier in the day that searchers were in the water, on the ground and in the air trying to find Jesse M. Haugen, 41, of Cambridge, Minn., and Reis M. Grams, 40, of Lino Lakes. They were part of a group of four that went over Curtain Falls on Saturday, at a site between Crooked Lake and Iron Lake on the Minnesota-Ontario border.

Two in their party survived: Kyle T. Sellers, 47, of Ham Lake, and Erik Michael Grams, 43, also of Ham Lake. Located at the group's campsite was Jared Jay Lohse, 33, of Cambridge.

In response to a request from Sheriff Gordon Ramsay, Walz authorized the National Guard to send in a Chinook helicopter and four crew members as part of the search campaign. The crew is tasked with airlifting a boat and other equipment from the Ely airport to the area where the two paddlers went missing, Walz's office said.

In June 2016 during a Father's Day trip, Walz's brother was fatally struck by a tree in the BWCAW as he sought shelter from a powerful storm. 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 tree fell on him. Craig Walz's son, Jacob, who was 14 then, also was hit by the tree and suffered severe injuries.

"No one expects their vacation to turn to crisis," read a statement from the governor, who was a U.S. House member at the time of his brother's death. "Yet, when four canoeists went over Curtain Falls in the BWCA, this became a reality.

"My family is intimately familiar with the fear and heartbreak these canoeists are feeling. We are praying for those involved and immensely grateful to everyone from the sheriff's office to the National Guard who are supporting this mission."

On Saturday at 7:20 p.m., a caller reported the canoes going over Curtain Falls, which is more of a slope than a steep drop, the Sheriff's Office said.

"We are putting on a full-court press," Skelton said. "We are throwing everything in but the kitchen sink."

Tools in use include boats, sonar and cadaver dogs along with personnel scanning an ever-widening area from the falls, Skelton said. He said law enforcement has "people who are going in and staying through the weekend."

As for the likelihood that no survivors will be found after so much time has passed, Skelton said, "We are transitioning to that point."

Conditions for the search are a mixed bag, the commander said. While skies have cleared up after recent rain, the water has since risen "more than a foot to become a bit more dangerous."