The scars remain but traumatised communities are starting to heal as a state memorial honoured the lives lost and the heroes forged in the New South Wales bushfire crisis.

A public state memorial was held at Sydney Olympic Park on Sunday to recognise the devastating toll of the bushfires that ripped through much of NSW.

Thousands of homes were damaged or destroyed and 25 people died in the bushfires since October.

The Rural Fire Service commissioner, Shane Fitzsimmons, told Sunday’s service each death served as a tragic reminder of the horror summer.

“Each one of those is a story of grief, of profound loss, and great sadness, of lives cut short, and of families being changed forever,” he said.

“To the families and loved ones of those that have been lost, and who are here today, we know your hearts have been broken over recent months and we are truly blessed that you’ve made the effort to be here today.”

The families of victims entered the memorial through a guard of honour, with a row of 25 candles laid out at the front of the stage to mark each life lost.

Six sets of boots were symbolically placed at the memorial for the three American airmen who died in a firefighting plane crash near Cooma and the three RFS volunteers who died fighting fires.

Boots representing the three RFS firefighters who died in the NSW bushfires and the three Americans who died in a water-bombing tanker crash. Photograph: Cameron Spencer/Getty Images

Captain Ian McBeth, first officer Paul Clyde Hudson and flight engineer Rick DeMorgan Jr were killed when their C130 water-bombing tanker crashed north-east of Cooma.

DeMorgan’s wife, Rebekah, who travelled to the service from the United States with her two children, said the support and love she had received was “phenomenal”.

RFS volunteers Geoffrey Keaton and Andrew O’Dwyer died when a tree hit their tanker south-west of Sydney, while Samuel McPaul died when a firestorm flipped his truck.

O’Dwyer’s daughter, Charlotte, and Keaton’s son, Harvey, laughed and chased each other during speeches.

Charlotte O’Dwyer, daughter of firefighter Andrew O’Dwyer, reaches out to Harvey Keaton, son of RFS deputy captain Geoffrey Keaton, during the service. Photograph: Cameron Spencer/Getty Images

The prime minister, Scott Morrison, spoke of a black summer underscored by unrelenting grief.

“In every case, our firefighters confronted the fire by relying on the love that was behind them,” he told the memorial.

“We’ve lost firefighters, aviators, farmers and civilians alike this summer. All carried within them, even until the end, the DNA of our universal language – I love you.”

The NSW premier, Gladys Berejiklian, said the work of those battling the bushfires was awe-inspiring.

“As our state faced massive threat to life and property, brave people went out to face the danger head-on and they did not flinch,” she said.

“Fatigued, traumatised and overwhelmed, they kept coming back, day after day, week after week, and month after month.”

Firefighting crews from across the state were among the hundreds of people who travelled to Sydney’s Qudos Bank Arena for the memorial.

The Dunmore RFS brigade deputy captain, Ian Cox, travelled to the memorial from Illawarra as a sign of solidarity with other crews.

“We are here out of respect for those that lost their lives,” he said.