AUBURN — Powerful memories of 9/11 pulled at emotions among uniformed firefighters and policemen, as well as those who came to pay respects to victims of the terrorist attacks 12 years ago.

A single sentiment, “We must not forget,” was echoed by several speakers at the Auburn Fire Department’s memorial service Wednesday morning.

Chief Frank Roma noted that as the years go by, fewer and fewer communities around the country choose to get together to remember Sept. 11, 2001.

“The numbers don’t change, though,” he said, referring to the loss of nearly 3,000 civilian lives, and more than 400 emergency-service personnel, mostly firefighters, in New York City.

“But there’s one number that does change, and that’s the number of people who continue to suffer,” he said, emphasizing increased cases of cancer attributed to working in the hazardous rescue conditions and post-traumatic stress, which affects countless people across the country on a daily basis.

“Probably the hardest challenge is to remain vigilant and prepared in light of recent events such as those in Boston,” Roma said, referring to the Boston Marathon bombings in April.

He paid tribute to men and women of the nation’s armed forces. “As we come together to remember what happened on this 12th anniversary of 9/11, I would ask that we continue to do all that we can.”

Auburn police Chief Phil Crowell told the audience and his fellow emergency responders, “As we look at events that are unfolding even today, we need to be vigilant on the home front and be sure that we are keeping our communities safe. It’s our local first responders who are on the front line here at home.”

The program took place a few feet in front of a twisted, 12-foot steel beam recovered from wreckage of the World Trade Center’s twin towers in New York City. The beam is permanently installed and displayed at the left front of the Auburn Fire Department’s Central Station on Minot Avenue.

Just before 8:46 a.m., the time at which Flight 11 hit the first tower, the Auburn Fire Department Honor Guard performed a brief ceremonial routine in recognition of the fallen emergency personnel. A large silver bell was sounded several times in their honor.

Deputy Chief Geoff Lowe of the Auburn Fire Department delivered closing remarks.

A floral arrangement was placed at the base of the memorial and a moment of silence was observed.

Cathy Brousseau was among those in attendance who were deeply affected by the ceremony and the opportunity to remember the victims. She said she works on fire equipment repairs, but her attendance at the ceremony was particularly important because she has a friend who lives in New York and who closely experienced the 9/11 tragedy.

“We need to remember,” she said.

Another attendee was Patti Julian, who said she has a son who was in school with the daughter of one of the hijacked planes’ pilots.

“It changed my life,” she said.