For Harold Schapelhouman, it's been 20 years, but the memories are still vivid.
"The smells. Decomposition. Burning flesh. Smoke. Destroyed buildings," he said. Back in September 2001, Schapelhouman was part of a California search and rescue team sent to New York City after the 9/11 attacks.
An experience, he says, is almost indescribable.
Something he's never been able to forget.
"The gates of hell is probably a good way to describe it. Or war of the worlds," Schapelhouman said.
But beyond the mental toll, for Schapelhouman and his teammates, there was also a physical price to pay.
Out of the 68 people on Schapelhouman's team, 47 of them, or about 70%, have suffered health issues in the years after 9/11. Those health issues, Schapelhouman believes, were caused by the so-called plume that engulfed the rubble of the World Trade Center for weeks after the attack.