A construction worker died at Martin Luther King Jr. Middle School last Tuesday, the day before the new school year began.

About 12:45 p.m., Oscar Marquez, 62, was reportedly run over by a big rig that rolled down an incline as employees were laying asphalt near the middle school’s new track and field, according to Berkeleyside.

The Alameda County Sheriff’s Office Coroner’s Bureau confirmed the cause of death as extensive blunt trauma, which can include broken bones, internal bleeding and multiple other injuries to the body.

The report detailing the exact circumstances of his death is unavailable at the moment but will become public in a matter of weeks or months, the coroner’s office said.

California Occupational Safety and Health Administration, an agency that enforces worker health and safety practices, began a six-month investigation last Tuesday, according to CBS.

Marquez worked for a company called Robert A. Bothman Construction. Established in 1978, the company has two branches — one in San Jose and another in Hawaii.

Since 2003, the company has had one “serious” safety violation that resulted in a $300 penalty, according to a database by Cal/OSHA.