A two-foot-long drone apparently flown by a hobbyist crashed on the White House grounds Monday in an extraordinary, if unintended, breach that raised fresh questions about the president's security — and a growing threat from the sky, reports the Associated Press .

A man later came forward to say he was responsible for the mishap in the middle of the night and hadn't meant to fly the drone over the complex, officials said. "Initial indications are that this incident occurred as a result of recreational use of the device," said Secret Service spokesman Brian Leary.

President Barack Obama and his wife, Michelle, were overseas when the quadcopter struck the southeast side of the grounds at about 3 a.m. Daughters Sasha and Malia stayed behind in Washington; it was not known whether they were at the mansion.

Officials believed the intrusion to be the first of its kind on the White House grounds, although not the first in the vicinity.

Police, fire and other emergency vehicles swarmed the White House just after the crash, with several clustered near the southeast entrance to the grounds. The White House was dark and the entire perimeter was on lockdown until around 5 a.m. when those who work there were allowed inside.