The first thing greeting Michael Hingson and his guide dog, Roselle, was the choking stench of jet fuel wafting down the north tower of the World Trade Center.

Hingson hadn't seen what happened -- the 51-year-old has been blind since birth. But it wasn't hard to figure some sort of aircraft had struck the building with tremendous force at 8:45 a.m. Tuesday.

Quickly, he told the few people in his office to get out of there and suggested they take the stairs because he believed the elevators surely wouldn't be working.

He had no idea what was happening. The Palmdale native, well-versed in earthquakes, said he only knew the rocking skyscraper was in terrible trouble -- and that he was pretty much alone. On the 78th floor.

"The office was empty except for myself, David, Frank and Roselle," he said. "I took a moment to call my wife and tell her there was an explosion at the World Trade Center and that I'd be home as soon as I could."

With that, he hung up the phone, grabbed the harness for Roselle and began issuing the commands that told the yellow Labrador retriever it was time to go to work.

But the dog, who had only been his guide for nine months, was already raring to go. She had been, in fact, since the initial impact that jarred her from an early morning slumber under Hingson's desk.

"She had already jumped up from there," Hingson said. "Usually she doesn't even stir when the wind shakes the tower."

While Frank described to Hingson how flaming chunks of debris were tumbling past their window, Roselle led him through the disheveled office and, eventually, to the stairwell.

"The crowds weren't huge at first," Hingson said. "But as we started making our way down, they got bigger."

It was getting hot, too, with temperatures in the stairwell climbing higher than 90 degrees. Hingson was sweating and Roselle was panting.

By the time they got to about the 50th floor, United Airlines Flight 175 had slammed into the south tower of the World Trade Center -- something he wouldn't know about until later.

Instead, the smell of jet fuel was getting stronger and soon he felt people bumping into him as Roselle, Frank and he continued downstairs.

The problem was, the people bumping into him were going the wrong way.

"I heard applause and was told they were firefighters," he said. "I clapped a few on the back, but I was scared for where they were going."

He should have been worried. Temperatures in the north tower were scorching the top part of the building at more than 1,000 degrees. And that heat was working its way through the stairwell each time people opened a door in an attempt to escape.

Others were worried, too. As news spread across the country about the terrorist attack on the twin towers, Kay and Ted Stern watched the news, horrified, from their Santa Barbara home.

The Sterns knew Hingson worked in the World Trade Center and had met him in December 1998 when they went to visit him and Roselle -- the puppy they had helped train for her eventual career as a guide dog.

"We had several friends in New York, including Hingson, and we sent e-mails immediately and asked for them to respond so we would know if they were OK," Ted Stern said.

At that time, however, Hingson, wasn't even sure he would be all right. The stairs were thick with people clambering down -- not stampeding, but moving quickly. And Hingson was worried about Roselle.

The dog had begun panting heavily, her throat scratched by jet-fuel fumes. No air was circulating and Hingson knew she was thirsty. Frank stayed with both of them and they finally reached the lobby of the building.

"A lot of pipes had broken and there were puddles on the floor," he said. "Roselle was stopping to drink some of the water, so I knew she was very thirsty."

It had taken them 50 minutes to get down the stairs and it took them another 10 minutes to actually get out of the building and onto the street.

The plan was to get to Frank's car and drive away, but at 9:50 a.m., that plan was scrapped.

"I heard the second tower collapsing," Hingson said. "It sounded like a metal and concrete waterfall. We started running for the subway."

He heard the shrieks of terror and yet Roselle remained focused on her task. He kept the commands simple --left, right -- and a police officer steered them into the subway.

When they emerged, Hingson was told the north tower was gone and the south tower smoldering near the top.

"It was unbelievable," he said. "I felt lucky to be out of there. But I wondered about the firefighters."

About 20 minutes later, while they were making their way from the World Trade Center, the south tower caved in on itself, sending a rolling gray cloud of ash, glass and debris toward them.

"The air was filled with crud," he said. "A woman nearby couldn't see because she had stuff in her eyes, so Roselle and I helped her."

Everyone was coated with the soot of what had once been two 110-story buildings. If Hingson could have seen her, Roselle had become a gray Labrador.

Because there were no trains operating that day, Hingson had to stay at a friend's house in Manhattan on Tuesday night before going home to his wife in Westfield, N.J., on Wednesday. He then began the long process of e-mailing everyone who was waiting to hear from him.

The Sterns finally heard from him Friday, after Hingson contacted the San Rafael-based Guide Dogs for the Blind Inc.

Joanne Ritter, spokeswoman for the nonprofit company that supplies guide dogs around the country to the blind, said Roselle was the first puppy the Sterns had raised to be a service dog.

The Sterns, for their part, said Hingson's story has inspired them to continue working with service dogs.

"We're training our fourth dog now," she said. "But Michael's story sure gives us a lot of validation."

David Montero's e-mail address is dmontero@insidevc.com.