For retired New York City police officer Ivan Castrillo, images of September 11, 2001 continue to come to life in his mind.

Twelve years ago, the first responder arrived at Ground Zero shortly after the second tower fell. He worked the scene for six months and says the details of that day are still vivid.

"All I saw was a tidal wave of smoke, debris, just rumbling, just rolling," said Castrillo.

For months, Castrillo breathed in all those toxins. He said he started getting sick in 2008.

Castrillo is part of the World Trade Center Health Program that treats and tracks the medical conditions of 9/11 responders.

"Since 9/11 and since I started becoming ill, this is the only program that has actually reached out," said Castrillo.

From COPD (Chronic Obstructive pulmonary Disease) to post traumatic stress disorder and gastrointestinal problems, Castrillo says he’s been diagnosed with several 9/11-related illnesses. The retired police officer says he fears becoming a statistic.

"Many people have already been diagnosed and many have already died of cancer,” he said. “And that’s something that I get monitored every year."

As Castrillo deals with multiple medical problems, he says he’s thankful to be alive.