"It looks like a war zone here," Landry told WMTW. "The newly constructed building is gone. The adjacent building is half down. (Firefighters) are hosing down what debris is left of the building. Not much."
The explosion took place at the LEAP building, according to the Sun Journal. The nonprofit group works to empower people who have developmental, cognitive and intellectual disabilities, told the Sun Journal that his home shook during the explosion, knocking pictures off his walls. He said when he went outside to investigate, he saw "complete chaos" and "complete devastation."
"It was white insulation, materials everywhere," he told the Sun Journal. "I was dumbfounded."
It was not immediately clear what caused the explosion, which sent debris and smoke into the sky before 8:30 a.m., though Peck said a preliminary investigation pointed to a possible gas explosion.
"It looks like it may have been a propane or natural gas leak," Peck said at a news conference. "That's in the very early stages of investigation."
Police did not immediately identify the firefighter killed in the explosion, citing the need to notify the firefighter's next of kin. Maine Gov. Janet Mills told reporters she knew the slain firefighter.
"Our hearts go out to all the families of the injured and the deceased and all the people in the community," she said.
Peck said Farmington fire Chief Terry Bell was among the people injured. A majority of the victims suffered burn injuries that appeared to be consistent with a building explosion, he said.
The explosion took place at the LEAP building, according to the Sun Journal. The nonprofit group works to empower people who have developmental, cognitive and intellectual disabilities, according to the group's website.
Mills said the state Fire Marshal's Office would conduct an investigation into the cause of the explosion.
"Our hearts go out to all those impacted by this tragedy, especially to the loved ones of the firefighter lost and others injured," she wrote in a Twitter post. "I am grateful for the work of first responders who are at the scene and urge Maine people to avoid the area."