Video: 'Watergate: The 18 ½ Minute Gap and Haldeman's Notes'

(Tuesday, June 20, 1972, 11:30 a.m.-1:00 p.m. EDT; during the Watergate scandal) — On their first day back at the White House after the June 17, 1972, break-in of the Democratic National Committee headquarters at the Watergate complex and the arrest of five Nixon re-election operatives, President Richard Nixon and Chief of Staff H.R. Haldeman met today in the Oval Office.

When the tape recording of their conversation was later subpoenaed by a special prosecutor, it was found that several minutes of the tape had been erased, creating the notorious 18 1/2-minute gap.

Video: 'The Final Report: Watergate (National Geographic)' (June 20, 1972)

The contents missing from the recording remain unknown, though the gap occurs during a conversation between Nixon and H. R. Haldeman, three days after the Watergate break-in.

Nixon later claimed not to know the topic or topics discussed during the gap. Haldeman’s notes from the meeting show that among the topics of discussion were the arrests at the Watergate Hotel.

Video: 'Who Erased 18 Minutes of Nixon Watergate Tapes?'

According to Nixon’s secretary Rose Mary Woods, on Sept. 29, 1973, she was reviewing the tape when she made “a terrible mistake” during transcription. While playing the tape on an Uher 5000, she answered a phone call. Reaching for the Uher 5000 stop button, she said that she mistakenly hit the button next to it, the record button.

For the duration of the phone call, about 5 minutes, she kept her foot on the device’s pedal, causing a five-minute portion of the tape to be rerecorded. When she listened to the tape, the gap had grown to 18 and 1/2 minutes. She later insisted that she was not responsible for the remaining 13 minutes of buzz.