Sean Benschop, the crane operator who assisted in the demolition of a building in Philadelphia when a wall collapsed onto a nearby store killing six is being held in police custody after surrendering on Saturday.

The 43-year-old will be charged with six counts of voluntary manslaughter, 13 counts of recklessly endangering another person and one count of risking a catastrophe, Associated Press reported.

Benschop was assisting with the demolition of a four-story building on Market Street in Center City on Wednesday when one of its walls fell on a nearby Salvation Army thrift store, killing six and injuring 13 others.

A toxicology report showed that Benschop was high on marijuana while on the job. It stated that "he was unfit to perform safety-sensitive, job-related duties" and pointed out that Benschop was an "active recent user of marijuana," according to the Philadelphia Inquirer.

Benschop’s lawyer, Daine Grey Jr., told the media that his client was not responsible for the collapse and that it was an accident.

"This was an accident, but Mr. Benschop is not responsible," Grey told AP. "We believe in time the facts will show that he is not responsible and that the responsible party will be held accountable."

Grey added that in the 13 years Benschop has been working as a heavy equipment operator, he has always had high regard for the safety of those around him.

"He has been doing this for more than 13 years. He is very experienced. He has worked for a number of contractors throughout the region. All of the contractors have found him professional and found that he did his work with the highest regard for the safety of those around him."

According to the Philadelphia Inquirer, Benschop has been arrested on a minimum of 11 occasions and has been convicted of 16 traffic violations. Twice in the 1990s, he was sentenced to prison on drug-related charges, the paper said.