The South San Francisco Fire Department wrote on social media shortly after 8 a.m. about the boat fires, which prompted a response by multiple fire agencies.
Ashley Pelayo captured a dramatic video of the fire on her cellphone.
"It was terrifying. I saw it from the parking lot," said Pelayo. "There was a cloud of smoke so I came rushing over here. I called 911 immediately because I heard an explosion no soon after."
Kristen Behring, who works nearby was out for her morning walk.
"I could hear somebody yelling," said Behring. "I smelled the smoke, I heard the sirens. I heard the billowing of the clouds and fire about 20 feet in the air."
Behring said she initially only saw one boat on fire and when she got closer, she realized it was three.
The fire department explained what they came across.
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"The three of them were moored together, caught fire, and spread apart," said Battalion Chief Bryan Saenz with South San Francisco Fire.
Behring learned that two people who lived on the boats had to be rescued. That development brought tears to her eyes.
"I just hope they are OK," said Behring. "I know the folks that live in these boats. There are several of them. They dock the boats and they come out and frequent the establishments.
Pelayo, who captured the intense flames on her cellphone, called 911.
She and others onshore were stunned to learn about the people rescued.
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"I saw people jumping out of the boats. There was one person who was still clinging on," said Pelayo. "The person couldn't swim. That was the first thing he yelled, 'I can't swim...' It wasn't until the rescue team came and tried throwing over the life raft, the person was like 'I can't swim' so the rescue crew had to get closer, throw it again so the person could actually hold onto it."
One person went to the hospital with minor injuries, according to the fire department.
Redwood City Fire and South San Francisco Fire managed to put out the fire on all three boats.
The U.S. Coast Guard and Harbor Patrol were also on hand to help with rescues.
Crews helped deploy booms and to help contain any oil and debris.