6 Secret Service Safeguards Breached By White House Intruder

— -- There were at least six safeguards that failed when a man jumped the fence and got deeper into the White House, according to reports.

Secret Service Director Julia Pierson appeared today before a House Committee over the biggest breach in security since she took over the post in March last year.

"I take full responsibility. It will never happen again," Pierson said at the beginning of the hearing without elaborating.

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Though the agency's spokesperson initially said that former veteran Omar Gonzalez was apprehended just inside the North Portico doors during the September 19 incident, authorities have now said that to be false.

Further details first reported by The Washington Post indicate that there were a half dozen steps that were not taken by the Secret Service during the close call, just minutes after the Obamas had left the building.

"How on earth did it happen?" Chairman on Oversight and Government Reform Congressman Darrell Issa said in his opening statements at Pierson's hearing this morning.

"The fact is the system broke down on September 19," Issa added.

Here's a step-by-step look at what happened, according to three sources quoted by The Washington Post:

According to The Washington Post, people familiar with the incident said that the officer may not have felt that they could release the attack dog because there were other Secret Service officers pursuing Gonzalez by foot, and the officer may have feared that the dog would attack the Secret Service agents rather than the intruder.