TAMPA ó Shortly before 9 a.m. on a beautiful morning 17 years ago, Greg Amira was making his way up to his office on the 73rd floor in the south tower of the World Trade Center.He felt the building shake."I assumed Building No. 1 was hit," Amira said. "I thought it was a bomb."Amira, a vice president of Morgan Stanley at the time who now lives in Trinity, delivered a moment-by-moment account Tuesday of his harrowing experiences as a survivor of the 9/11 terrorist attacks. He spoke on the anniversary of the attacks, to a group gathered at the 9/11 Fallen Heroes Memorial in Ybor City.All told, nearly 3,000 people died when four airliners were used as missiles in New York; Washington, D.C.; and a field near Shanksville, Pa.For Amari and others in the south tower that day, the loud noise in the next building started a race down the stairwell. They did not know yet that al-Qaida hijackers had crashed American Airlines Flight 11 from Bostonís Logan Airport into the north tower.As Amari reached the vicinity of the 20th floor, United Airlines Flight 173 from Logan hit the tower above him."I was on the phone, trying to make a call, when it went dead," he said. "All of us pretty much dropped to our knees from the rumbling and shaking."When he finally reached the outside, he looked up and saw segments of the building in flames. The son of a New York City police officer, an Army reservist with military training, his instincts kicked in and ó against the protests of colleagues ó Amira headed back toward the buildings.By that time, most of the injured were coming from the north tower."They had severe injuries. I donít want to get too graphic, but you can imagine."RELATED: 9/11 remembered 17 years laterWatching the unfolding carnage, Amira noticed firefighters from around the region pouring into the building. Those from stations nearby knew that renovations made after the bombing of the World Trade Center in 1993 split the stairwells so firefighters and their equipment could climb one section while evacuees descended the other.Amira ran into firefighters who didnít know."†ĎGet out of my way, Iím a fireman,í†" they told him, and he explained to them the new setup.Another crew came by and Amira pointed them to an elevator, which he learned could be operated manually by a pulley system.Then there was another loud rumble."I hit the ground as fast as I could."Looking up, he saw sparks coming from a lobby. Then more sparks. Then the glass blew out, followed by a burst of flames."The first thing that came to my head is that I am a jerk for leaving my daughter without a father. For what? It was not my job."But he and a firefighter were shielded from the blast and falling debris by a hunk of wall marble.The firefighter asked Amira to check on a buddy next to him."I grabbed his elbow and upon pulling, realized I was holding an arm." The first firefighter "smacked it out of my hands and asked how we get out of here."Sunlight began to filter through the windows and Amira could see hundreds of bodies. He and the firefighter checked quickly for survivors but found none. They crawled through the rubble to reach the Westside Highway.Amira heard yet another loud noise and looked up.It was just before 10:30 a.m. The south tower was gone. The north tower was collapsing."To this day I recount every second, every moment, every smell," said Amira, who finished that day in a hospital, his elbow bone sticking out of his left arm, a bruise on his head, and shrapnel wounds on his neck, back, buttocks and legs.After his speech Tuesday, Amira, who now runs the non-profit Wounded Vets Association, looked out in appreciation over the group in attendance. They had come to honor him, those who perished on Sept. 11, 2001, and the nearly 7,000 U.S. service members who have died in the wars that resulted."Iím really gladly shocked," Amira said, "that there is still so much remembrance for that day."Contact Howard Altman at [email protected] or (813) 225-3112. Follow @haltman.