By Steve Tawa

PHILADELPHIA (CBS) – It’s sentencing day for the contractor who oversaw demolition at the site of the deadly 2013 building collapse, at 22nd and Market Streets. A jury convicted him last October on six counts of involuntary manslaughter and other charges.

The pre-sentencing memo configured by the Philadelphia District Attorney’s office seeks a 25-50-year prison sentence for Griffin Campbell.

During the trial, the 51-year old Campbell took the stand in his own defense, claiming he was the fall guy for higher ups involved in the block-long demolition project.

Prosecutors say Campbell “pulled out the guts and spine of the building, destabilizing it by talking out floors and joists,” cutting corners that led to the collapse.

The only other person facing criminal charges, Campbell’s heavy equipment operator, Sean Benschop, who pleaded guilty to the same charges and testified at trial, will also be sentenced. His plea arrangement with prosecutors stipulates that he serve no more than 20-years in prison.

Campbell was offered but rejected the same plea arrangement.

Cambell’s defense lawyer shifted blame to the building owner and property manager, who were not charged, and the architect who was given immunity from prosecution for his testimony. He says they wanted it down quickly, so the vacant properties could be redeveloped.

Still to come, now scheduled for September – unless there is a settlement – a consolidated civil trial. Lawyers representing the six victims who died and others who were injured named 18-people or entities, including Campbell, the building owner, property manager, architect and the Salvation Army.