(DNAINFO)  Murray Weiss | September 8, 2016 — Mark Rossini said the tragedy could have been avoided with better communication between the FBI and CIA.

Everyone has a 9/11 story.

The most heartbreaking accounts involve the loss of a loved one or close friend in the worst attack ever on America soil.

Mark Rossini has that. But his sorrow is compounded by a powerful emotion — guilt.

“It is the guilt of knowing that 9/11 100 percent did not have to happen,” said Rossini, a former top FBI agent who worked at the Central Intelligence Agency.

Fifteen years ago this Sunday, Rossini, the Bronx-born son of a blacksmith and social worker, was the FBI’s point man inside the CIA’s covert “Alec Station,” a specialized counter-terrorism and intelligence unit devoted solely to defeating Osama bin Laden and al Qaeda.

Within two hours of the attack, the names of Khalid al-Mihdhar and Nawaf al-Hazmi showed up on the manifests of the hijacked jets that killed nearly 3,000 people.

The dead included Rossini’s cousin, a high school friend, his best friend’s mother-in-law and his beloved former FBI boss, John O’Neill, a bin Laden expert who had just taken a job as head of security at the World Trade Center.

Rossini was sickened at the sight of the two names because he knew the CIA was aware — for two years, it turned out — that the al Qaeda terrorists had been living in the United States and that the CIA had “purposely” never informed the FBI about them.

Source: FBI Agent Still Plagued by Guilt Because He Didn’t Stop 9/11 – Civic Center – DNAinfo New York