As thousands of people fled the chaos and danger at Ground Zero on Sept. 11, 2001, police officers, firefighters, medical workers and other rescuers moved toward the devastation.

Among them was NYPD K-9 Officer Peter Davis and his search dog, Appolo. The pair joined other search teams combing through the massive pile of rubble, looking for signs of life.

“We went to different areas trying to search and trying to find someone who was alive,” Davis recalled.

The work was exhausting and dangerous. K-9 teams often spent 12 hours or more searching the pile, navigating a landscape of unstable debris, sharp metal and broken glass. The dogs themselves faced cuts, burns, dehydration and other injuries as they worked through the rubble.

Keeping the animals healthy enough to continue meant bringing veterinary care directly to the scene.

At the request of the NYPD, Suffolk County SPCA Chief Roy Gross brought the agency’s mobile veterinary hospital to Ground Zero. The unit was brand new at the time and was parked just a few blocks from the site by 6 p.m. on the day of the attacks.

About 200 veterinarians ultimately treated roughly 350 search-and-rescue and therapy dogs involved in the recovery effort.

The conditions were unlike anything many of the veterinary teams had encountered. Dr. John Charos was among those who cared for the animals at Ground Zero.

“Everything was still smoldering, burning,” Charos recalled. “There was molten steel... sharp pieces of metal, jagged pieces of glass. It was a mess down there.”

Gross remembers being told at the time, “We cannot do this without you here.”

“I’m sure we made a big difference,” he said.

Charos remembers the importance of their mission: “You went out there, did the job that was needed out there.”

For Davis, the time at Ground Zero — and the memory of those who answered the call — remains deeply personal.

“I don’t want it to ever be forgotten what we did down there and what we tried to do,” he said.

Twenty-five years later, the stories of the rescuers and their K-9 partners remain a testament to courage in the face of unimaginable danger — and to the veterinarians and volunteers who put themselves at risk to care for those four-legged heroes.