SLIPPERY ROCK — With the help of New York City firefighters, Shiya Ribowsky ventured deep into the 11-story-high pile of rubble of the World Trade Center just a few days after Sept. 11, 2001.

He was asked to collect something from the scene to identify what they thought to be one of their fellow servicemen, a Port Authority of New York and New Jersey policeman. Ribowsky was able to extract nothing more than a toe to take back to his office at the city's medical examiner.

As the director of the world's largest medical examiner's office, some might think this was all in a day's work. But for Ribowsky, the incident affected him deeply since he saw firsthand the conditions that workers were dealing with following the collapse of the World Trade Center.

"We owe them a debt of gratitude," he said of the workers who combed through the rubble to help his office identify 1,600 of the victims of the tragedy.

His story came at the end of a 90-minute speech, part of a four-part lecture series titled, "Science and Technology in the New Age." The series celebrated the recent opening of Slippery Rock University's three-story, $14.5 million Advanced Technology and Science Hall and the speech was held in the hall's auditorium.

Much of what Ribowsky described was the process of identifying remains of World Trade Center victims. That included the careful hand sorting that was done by so many during the months that followed the tragedy, he said.

There were 2,749 victims, and the office was able to identify 85 percent of the 1,600 by DNA evidence alone, Ribowsky said. And without modern forensic science, including some that was developed during the tragedy, he and his co-workers couldn't have reached that number, he said.

"If that disaster happened in 1980, less than 200 victims would be identified," he said.

Ribowsky said that 1,600 included 16 misidentifications, an extremely low number if you consider the numbers. His office sorted and identified 21,000 individual remains, sometimes consisting of only a bone or bone fragment. Ribowsky gave some background on the height of the towers, the planes and the fires that burned for months that all worked together to make identification of victims nearly impossible.

However, the number of people identified by DNA could be increased greatly if people had accurate live samples of their DNA available, Ribowsky said.

"The way we identify someone is we compare something from the body to something from the victim's life," he said.

For the World Trade Center disaster, that meant connecting with family members, collecting a razor that the person used recently, or something else that contained that person's DNA. This was no small task because there were 100,000 family members to interview, he said.

In several years, Ribowsky predicted that people will have a DNA "footprint," recorded somewhere when they are born, much like the regular footprint that they take of babies. The only thing holding this back now isn't science, but politics and paranoia, he said.

"It's ludicrous that they aren't doing this already," he said.

"Most people are worried about if the government gets ahold of my DNA, they'll clone me," he said. At the same time, no one thinks twice about giving blood and sending it to a lab, where someone could, theoretically, collect DNA.

Ribowsky worked for the medical examiner's office for 15 years. He now works as a forensic consultant to NBC's "Law and Order," and recently co-authored a book titled "Dead Center: Behind the Scenes at the World's Largest Medical Examiner's Office" discussing events related to forensics in the public eye.

Despite his serious topic, Ribowsky kept his tone light, taking great care to describe the importance of the coroner in the movie, "The Wizard of Oz." In that case it was simple, with the first witch dying due to blunt trauma caused by a farm house falling from the sky. The manner of death, Ribowsky said, was an accident.

"If the coroner had communicated better to the witch's sister at the beginning, she wouldn't have kept trying to kill Dorothy," he said.

Ribowsky also engaged the audience when he could.

Asking two roommates to stand up back to back, he demonstrated how hard it was to remember what someone close to you is wearing. The question often comes up when he's trying to identify loved ones. Ribowsky makes sure his wife knows what he is wearing if he takes an airplane trip. If she doesn't see him that morning, he calls to describe the outfit he had on when the plane took off.

During the grisly description of his work on Sept. 11 victims and the graphic photos he showed, the crowd of about 100 was silent.

Nicole Bauman and Elliott Butler, two SRU students assigned to attend the lecture by their professors, agreed after the talk that it was well worth their time.

"It was such an interesting perspective of someone who was right there," Butler said.

Bauman said it wasn't a real technical talk, which is why she enjoyed it. "It wasn't all forensics," she said.

Jenna Wilcox, forensic chemistry major, said she would have attended the talk for a class or not.

"I was really excited to see if this is really what I want to do," she said. "I also wanted to see what it was like in other areas (of the country)."

The lecture series opened Monday with Roland "Bud" Mertz, deputy director for critical infrastructure and community liaison for the Pennsylvania Office of Homeland Security, addressing the topic "Technology and the War on Terror." Tamra Schiappa, assistant professor of geography, geology and the environment, on Tuesday addressed the issue of women working in the field of geology.

The week concludes with a 12:30 p.m. address today by Joe Murzyn, executive assistant to the attorney general of Pennsylvania, offering "Technology and Identity Theft."