SAN FRANCISCO INTERNATIONAL AIRPORT (CBS SF) – Terminal 3 at San Francisco International Airport was cleared Friday morning after an unauthorized access to the terminal, an airport spokesman said.

A person gained access to the terminal because of a “procedure breakdown” between 3:30 a.m. and 4 a.m. Friday, airport spokesman Mike McCarron said.

KCBS’ Anna Duckworth Reports:

Everyone in the United Airlines domestic terminal was cleared, and had to go through security screenings again to reenter the terminal, McCarron said.

Passengers began reentering the terminal at around 5:30 a.m. Friday and the evacuation has caused long lines at security checkpoints.

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McCarron said that the airport expected to have the lines thinned out and to be back to normal operations by around 7:15 a.m.

While he could not comment on the nature of the unauthorized access, McCarron said that airport officials were currently interviewing the person who entered the terminal.

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