A small drone flying low crashed onto the White House grounds before dawn Monday, triggering a major emergency response and raising fresh questions about security at the presidential mansion. A man later came forward to say he was responsible and did not mean to fly it over the complex.

The man contacted the Secret Service, which protests the president and others, at midmorning after reports of the crash spread in the media. Secret Service spokesman Brian Leary said the man had been interviewed by Secret Service agents and was cooperating with the investigation.

"Initial indications are that this incident occurred as a result of recreational use of the device," Leary said. He added that investigators were interviewing others to corroborate the man's story, as well as examining evidence from the scene.

A U.S. official said the man is a Washington resident and that investigators don't currently have any reason to doubt his story. The official wasn't authorized to discuss the investigation publicly and spoke only on condition of anonymity.

Although President Barack Obama was not at home, the security breach prompted a lockdown of the entire complex until officials could examine the drone. The White House later said it did not pose a threat.

The agency recently has faced persistent questions about its effectiveness and ability to protect the president.

Four high-ranking executives were reassigned this month, and former Director Julia Pierson was forced to resign last year after a man armed with a knife was able to get over a White House fence and run into the executive mansion before being subdued.

The drone crashed on the southeast side of the White House grounds just after 3 a.m., Secret Service spokesman Brian Leary said.

The device was described as a two-foot-long (half meter) quadcopter — a commercially available unmanned aircraft that is lifted by four propellers. Many small quadcopters are essentially sophisticated toys that can also be useful for commercial operations like aerial photography and inspections. Often weighing only a few pounds (kilograms), they sell for as little as a few hundred dollars or less, and were popular Christmas gifts last year.

The president and first lady Michelle Obama were traveling in India, but their daughters, Sasha and Malia, may have been at home. White House officials declined to comment on the daughters' whereabouts Monday, but ahead of the president's trip aides had said the daughters would remain in Washington so as not to miss school.

The incident was likely to reinvigorate a long-running public debate about the use of commercial drones in U.S. skies — as well as White House security.

House Oversight Committee Chairman Jason Chaffetz, a Republican and a chief critic of Secret Service leadership, said the agency has been working for some time to figure out how to deal with the threat posed by unmanned aircraft. He said a wake-up call came in 2013 when a camera drone crashed in front of German Chancellor Angela Merkel at a campaign event in Germany.

"Any time you can breach the White House perimeter, it's deeply concerning," Chaffetz said in an interview Monday.

Although remote-controlled airplanes and related toys have been available for decades, White House aides could not recall any similar incidents having occurred in the past. The incident comes just as policymakers are, for the first time, grappling seriously with how to integrate unmanned aircraft into the nation's skies.

The recent proliferation of inexpensive drones has prompted growing fears about potential collisions with traditional aircraft. Technological advances have also made it easier to equip drones with advanced capabilities such as cameras, raising privacy issues as well as concerns that such devices could carry weapons.

Industry experts said that to carry and fire a weapon, a drone would need more engines and more propellers than most commercially-manufactured quadcopters.

At the urging of the drone industry, the Obama administration is on the verge of proposing rules to permit commercial flights by small drones, but no date has yet been set for release of the proposal. Currently, the Federal Aviation Administration bans commercial drone flights — with some exceptions — and hobbyists are barred from flying drones above 400 feet (120 meters)in altitude or within 5 miles (8 kilometers) of an airport.

Airspace around the White House is heavily restricted to protect the president and other sensitive sites in the vicinity.