MINNEAPOLIS (AP) - Engineers have begun their investigation into what caused a natural gas explosion in Minneapolis that sent flames high into the air and scorched parked cars, but caused no injuries and minimal damage to buildings.

State Office of Pipeline Safety spokeswoman Kristine Chapin  says workers spent the night pumping water out of the hole in 60th street near Interstate 35W where the 20-inch gas line ignited.

She says in a typical investigation, engineers will dig out the damaged pipe and send it to a laboratory for rigorous analysis.

She says the state's inspection records of the line won't be released until the investigation is done, and there's no timeline for when that will happen.

The Thursday morning fire caused an eight-block area to be evacuated for several hours.

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