Escalators were stopped and flight information display screens were down.
Lines to check bags and head through security grew much longer than your average Wednesday outside of the holiday season.
"I'm like 'Am I in the Twilight Zone?'" Shantal Wallace, a San Antonio resident said. "That's the first thought I had."
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Wallace knew something was off the moment she got to SFO Wednesday morning.
"The door to get into the terminal was completely closed so it just threw me off because I thought, 'It's 7 a.m., it shouldn't be closed,'" she said. "It's the San Francisco Airport!"
SFO officials say a partial power outage impacted terminals 1, 3 and the international terminal.
It started around 5:30 a.m. Wednesday and while the outage only lasted a couple hours, the impacts lasted much longer.
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According to Flight Aware, more than 150 flights out of SFO were delayed before noon.
"Can't get no worse than this," Kevin Thapvongsa, a Minneapolis resident said.
Thapvongsa had just landed after an 11-hour flight from Korea.
He said the outage in customs forced passengers on his flight to wait on the plane for about 90 minutes. Lucky for him, he had a 15-hour layover to make his flight home to Minneapolis.
A spokesperson for SFO says a ground stop around 5:30 a.m. was related to their closed runway for construction.
They say their air traffic control tower never lost power during the partial outage.
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The outage happened the same morning Alaska Airlines is moving from Terminal 2 to the new Harvey Milk Terminal 1.
Starting Wednesday morning, almost every Alaska Airlines operation is moving, including ticket counters, boarding gates and baggage claim.
The only thing not moving right now is the Alaska Airlines lounge, which is staying in Terminal 2 until the new lounge opens in Terminal 1 next month.
The relocation comes as a part of Terminal 1's $2.5 billion renovation, which includes a brand new security check-point, additional gates and new concessions.