PHILADELPHIA (AP) -- The city's top prosecutor announced Monday he would convene an investigating grand jury to look into a building collapse that killed six people and injured 13 others last week.
District Attorney Seth Williams said the "scope and depth" of the grand jury process will help prosecutors, the city and others to "completely and appropriately investigate" what happened when a downtown building under demolition collapsed onto a neighboring Salvation Army Thrift Store, killing two employees and four customers.
"I know Philadelphians demand action. I heard their voices loud and clear," Williams said at a news conference. "We want Philadelphians to be patient as we gather all the evidence."
Police allege a heavy equipment operator, Sean Benschop, was high on marijuana when the collapse happened Wednesday. His attorney said it was an accident and his client is not responsible.
Benschop surrendered Saturday to face six counts of involuntary manslaughter, 13 counts of reckless endangerment and one count of risking a catastrophe. He is the only person currently charged in the collapse and is being held without bail pending a hearing June 26.
"Philadelphians have no shortage of opinions of the many people that should be held responsible for the perceived actions and inactions that may have played a role in the chain of events that led to the building collapsing," Williams said.
"While some may be held responsible in civil court, the role of the grand jury will be to hear from witnesses, to gather documents, to gather information and to then determine if anyone (else) should be held criminally responsible."
The grand jury will likely also "investigate the myriad municipal agencies and departments, and policies and protocols, surrounding the collapse," he said.
Also Monday, City Council was announcing the formation of a special committee to conduct a broad review of procedures and regulations regarding licenses and permits, construction and demolition, the certification of workers, building maintenance and other issues.
Since the collapse, officials have begun inspecting hundreds of demolition sites citywide. Mayor Michael Nutter said Friday that the city was preparing to implement sweeping changes in its regulations of building demolition.
A demolition permit indicates that contractor Griffin Campbell was being paid $10,000 for the job. Campbell's lawyer, Kenneth Edelin, has advised Campbell not to comment to the press, according to a woman who answered the phone at Campbell's home, and building owner Richard Basciano's attorney declined to comment.
Memorial services began over the weekend for some of the victims, who included a student at the Pennsylvania Academy of the Fine Arts, a retired secretary, a Liberian immigrant and a woman who was working her first day at the thrift store.
Myra Plekan, 61, who was rescued after being trapped in rubble for more than 12 hours, was upgraded Monday from critical to serious condition, said a spokeswoman at the University of Pennsylvania hospital. Another victim remains hospitalized at Thomas Jefferson University Hospital but his condition was not immediately available.
The 11 other survivors are all out of the hospital.
Associated Press writer Keith Collins contributed to this report.