The crane operator believed to be responsible for a June 5 building collapse in Philadelphia that killed six people and injured 13 was allegedly high on marijuana and codeine at the time of the accident. According to the Associated Press, city officials investigating the incident say that Sean Benschop, 42, tested positive for drugs in the hours just after the accident.

Benschop, who is currently missing, faces six counts of involuntary manslaughter, six counts of risking catastrophe and other charges, said Deputy Mayor Everett Gillison to the AP.

Police raided Benschop's home Friday, but did not find him. Calls to his phone are reportedly not being returned.

Police at the scene said that Benschop appeared intoxicated on the day of the accident, speaking in a barely-audible voice and seeming disconnected from his surroundings. He told officers he had been taking codeine since cutting his finger in a recent accident.

The demolition worker was operating an excavator device when he knocked part of the building being demolished on to a Salvation Army shop next door. Four customers and two employees -- one of whom was working at the store for the first time that day -- were killed when the Salvation Army building collapsed.

Benschop, who also goes by the name Kary Roberts, has been arrested at least 11 times since 1994 on charges varying from theft and possession of drugs to trafficking and weapons possession. He was sentenced to prison twice and accused of aggravated assault in January of 2012.

Accusations of negligence are being hurled at contractor Griffin Campbell, for whom Benschop was working. According to attorney Robert Mongeluzzi, Campbell violated multiple safety ordinances. The lawyer also cited building owner Richard Basciano for not choosing a more competent contractor.

"This is the most egregious construction accident I think I've ever been involved in," said Mongeluzzi to the AP.

Update, 4:21 p.m. EST: WCAU-TV reported that Benschop turned himself in to police detectives around 3:30 p.m. Saturday.

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