When Youngjin looked out of his office window and saw armoured trucks and immigration enforcement officers running around with guns, he was surprised, but not worried.
The young South Korean was certain it had nothing to do with him. He was in the US only for a few weeks on a short-term visa, he thought to himself.
Then the armed agents burst into his room and ordered him outside. They handcuffed him, before attaching chains to his waist and ankles, and loaded him onto a bus bound for a detention centre.
"I panicked and my mind went blank. I felt sick," he told the BBC, now back home in South Korea.
"I couldn't understand why I was being treated like this."
