Secret Service Director Julia Pierson resigned today following calls by high-ranking U.S. lawmakers from both parties for her to step down after recent security breaches. Congressional support for her eroded following Pierson’s poorly received testimony about the White House break-in. The interim director of the agency will be Joseph Clancy, a former special agent in charge of the president’s protective detail who retired in 2011.

The office of Sen. Chuck Schumer, the No. 3 Senate Democrat, and Sen. Lindsey Graham, a leading Republican, said earlier Wednesday that the senators would call for Pierson’s resignation on Wednesday. And Rep. Jason Chaffetz, a senior Republican on the House Oversight and Government Reform Committee, said Pierson should either resign or President Barack Obama should fire her.

House Speaker John Boehner said Pierson’s appearance before a House panel Tuesday “left us with more questions than answers.” Boehner stopped short of calling for Pierson’s resignation but backed a call for an independent investigation.

On Tuesday Pierson said that she takes full responsibility for the breach of White House security in which a man with a knife entered the mansion and ran through half the ground floor before being subdued.

She also said there have been six fence-jumpers this year alone, including one just eight days before Army veteran Omar J. Gonzalez jumped the fence on Sept. 19.

Pierson appeared Tuesday before the House Oversight and Government Reform Committee to face blistering criticism.

“The fact is the system broke down,” declared committee chairman Darrell Issa. “An intruder walked in the front door of the White House, and that is unacceptable.”

Not only that, he said, but the intruder penetrated at least five rings of security protecting what is supposed to be one of the world’s most secure properties.

“How on earth did it happen?” he asked. “This failure … has tested the trust of the American people in the Secret Service, a trust we clearly depend on to protect the president.”

Members of Congress briefed by the agency that protects the president and his family apparently weren’t told of the full extent of the breach. Details only emerged later.

Rep. Jason Chaffetz, a Republican, said Monday night that whistleblowers told his committee that the intruder ran through the White House, into the East Room and near the doors to the Green Room before being apprehended. They also reported to lawmakers that accused intruder Omar J. Gonzalez made it past a guard stationed inside the White House, Chaffetz said.

“I’m worried that over the last several years, security has gotten worse — not better,” Chaffetz said.

In the hours after the Sept. 19 fence-jumper incident, Secret Service spokesman Ed Donovan told The Associated Press that Gonzalez had been apprehended just inside the North Portico doors of the White House. The agency also said that night the Army veteran had been unarmed — an assertion that was revealed to be false the next day, when officials acknowledged Gonzalez had a knife with him when he was apprehended.

Pierson’s predecessor, Mark J. Sullivan, apologized to lawmakers in 2012 after details emerged of a night of debauchery involving 13 Secret Service agents and officers in advance of the president’s arrival at a summit in Colombia. Sullivan retired about 10 months later.

Details of how far Gonzalez got into the White House were disclosed Monday.

Citing multiple unnamed sources, The Washington Post reported that Gonzalez ran past the guard at the front door, past a staircase leading up to the Obamas’ living quarters and into the East Room, which is about halfway across the first floor of the building. Gonzalez was eventually “tackled” by a counter-assault agent, the Post said.

Getting so far into the building would have required Gonzalez to dash through the main entrance hall, turn a corner, then run through the center hallway halfway across the first floor of the building, which spans 168 feet (50 meters) in total, according to the White House Historical Association.

Since the incident, the White House has treaded carefully. Although White House spokesman Josh Earnest acknowledged the president was “obviously concerned” about the intrusion, he expressed confidence in the Secret Service as recently as Monday.

It would be untenable for any president, not just Obama, to pointedly criticize the men and women who put themselves at risk to protect his life and family. That inherent conflict of interest means Congress, not the executive branch, is the most effective oversight authority for the Secret Service, its agents and officers.

“The president and the first lady, like all parents, are concerned about the safety of their children, but the president and first lady also have confidence in the men and women of the Secret Service to do a very important job,” Earnest said.

Reporting by The Associated Press