Gov. Jared Polis on Sunday mourned the deaths of three firefighters killed while battling a wildfire on the Colorado-Utah border, calling the loss a tragedy for the state and the firefighting community.

The firefighters died Saturday while responding to a fire in the Knowles Canyon near the state line, according to initial reports. Two additional firefighters were injured and taken to a hospital.

“To the loved ones of those lost, and to their fellow crew members — some who are still battling the flames — know that the State of Colorado mourns alongside you,” Polis said in a statement.

The governor’s statement came a day after he declared a disaster emergency in response to the Snyder Mesa fire, which crossed from Utah into Colorado. The governor’s office said three fires — the Jones, Snyder Mesa and Knowles fires — have merged into the Snyder Mesa fire, which is estimated to have burned more than 28,000 acres.

The governor’s declaration activated the State Emergency Operations Plan, placing state agencies in charge of response, recovery and mitigation efforts for the Snyder Mesa fire. It also authorized the Colorado National Guard to assist in recovering the three fallen U.S. Wildland Fire Service firefighters.

“The State is working closely with the Bureau of Land Management and local officials and firefighters to deploy any and all resources needed to fight these fires, including the Colorado National Guard, and to recover the three firefighters who were lost,” Polis said.

Other elected officials and government agencies also expressed their condolences following the deaths.

Utah Gov. Spencer Cox said on social media that the state is mourning the loss of the firefighters.

“Today, we mourn three heroes who made the ultimate sacrifice protecting lives and communities along the Utah-Colorado border,” Cox wrote. “Please join Abby and me in praying for their loved ones, those who were injured, and every firefighter still on the line.”

U.S. Secretary of the Interior Doug Burgum said the firefighters were serving with the U.S. Forest Service and the U.S. Wildland Fire Service as part of a joint response to the fires.

“This is terrible news and a reminder of what our first responders risk every time they go out to prevent devastation and protect Americans from natural disasters,” Burgum wrote on social media.

He said federal officials are focused on supporting the firefighters’ families, friends and crewmates and pledged support for those affected.

“Their bravery, dedication and sacrifice will never be forgotten,” Burgum said.

The U.S. Forest Service also issued a statement Sunday.

“We stand with the U.S. Wildland Fire Service and our interagency partners in honoring the dedication, professionalism, and sacrifice of these firefighters,” the agency said.

Authorities have not yet released the identities of the firefighters. An interagency review and investigation is ongoing, according to the U.S. Forest Service.