It's not the kind of news conference that you leave and just forget about.

Late Tuesday, Philadelphia City Treasurer Nancy Winkler and her husband, Jay Bryan, met with reporters  to announce they've filed a wrongful death suit stemming from the June building collapse in center city that killed six people, including their 24-year-old daughter, Anne Bryan.

The couple engaged Robert Mongeluzzi, who's filed several other suits on behalf of the collapse victims, and the complaint has the usual language demanding compensatory and punitive damages. But Winkler said the suit is really about finding answers and holding people accountable.

"As we've had to walk this road the last three months, we just believe that this, as Jay said, just should never have happened," Winkler said. "And our main objective is to take whatever steps are necessary to make sure that no other parent has to go through this."

The couple called for the creation of an independent panel of national experts to advise the city on how to reform its regulation of demolition projects. And Winkler said they don't intend to develop information about the collapse to be sealed with a settlement.

"We want a trial," she said, so that every fact about the collapse becomes public.

"You know, this is a horror," Winkler said. "This is something that really doesn't even happen in the developed world. I think many people would like to minimize this, because it's just too hard for all of us to process,  that something this horrible happened in Philadelphia."

The suit names the building owners, the Salvation Army, the demolition contractor and others. It doesn't name the city, which her attorney says is legally protected from litigation in such a case.

The couple have started an Internet petition aimed at making the site of the collapse a memorial park.

 "It's important that we never forget this, that we understand why we need to spend the money to have a strong [licenses and inspections department]," Winkler said. "And we need to make sure that victims whose voices were silenced, who've never been able to fully live out their natural lives will be remembered. And we think that, if a park is there, it will be a small consolation and an opportunity for us to try and heal."

Mark McDonald, Mayor Michael Nutter's spokesman, said Tuesday night the mayor supports the idea of creating a panel of experts and plans to announce its appointment soon. Nutter also supports the idea of turning the park into a memorial, McDonald said, noting that the city doesn't own the lot and that it's involved in litigation.

It's worth listening to Nancy Winkler's recollection of the last moments she spent with her daughter, who lived with her parents in a house on 22nd Street, just a few blocks from the collapse site. I've posted that audio above.