His legs were crushed under the rubble and he suffered a minor heart attack, Jeffrey Goodman, the lawyer for Johnson's estate, said Tuesday.
Johnson could not breathe properly before being pulled out of the building wreckage about an hour after the collapse, Goodman added. The suit claims Johnson's "previous heart- and asthma-related issues were exacerbated" by the injuries he suffered that day.
Johnson spent nine days at Hahnemann University Hospital before being sent home in a wheelchair, Goodman said. He returned to Hahnemann on June 26 and died two days later.
Johnson, like some of the other victims, frequented the Center City store on Wednesdays, when it had sales, Goodman said.
In addition to the Salvation Army, the estate is suing STB Investment Corp., which owned the building being demolished; Richard Basciano, STB's principal owner; demolition contractor Sean Benschop; and architect Plato Marinakos.
Peter Greiner of Sprague & Sprague, the law firm that represents STB and Basciano, said Tuesday he had not yet seen the suit and declined to comment.
John J. Snyder, who represents the Salvation Army, also said he had not received a copy of the suit and could not comment on it. He said he disagreed with allegations in other wrongful-death suits in the collapse.
"The position we've taken all along is that the Salvation Army has done nothing wrong," he said.
Although Johnson died within a month, the complaint was not filed until a year later because his attorneys "wanted to make certain" that his death was a direct result of the building collapse, Goodman said.
"Medical records and a forensic pathologist have confirmed his death was caused by those injuries in this preventable tragedy," Goodman said.