'People were crying . . . there was chaos'

CAMBRIDGE -- A transformer exploded in the basement of a 17-story office tower in Kendall Square yesterday, killing an NStar employee and leaving more than 100 of the building's 800 workers and visitors suffering from smoke inhalation.

Workers at One Broadway described enduring some of the scariest moments of their lives as they fought down stairways filled with black, acrid smoke, their throats burning and eyes stinging. Many said they thought they would die. Some workers smashed windows on the sixth floor, lowered a ladder, and clambered to the roof of an adjacent parking garage, where they were rescued by firefighters.

It took about an hour to evacuate the building. More than 30 people were taken to hospitals and treated for smoke inhalation; at least 70 more were treated at the scene.

NStar officials identified the worker killed as Kevin Fidalgo, 28, a former high school football star who had worked with the company since June 2000. Christopher Carey, an NStar worker who was with Fidalgo performing routine maintenance on the transformer, was treated for smoke inhalation.

When the transformer exploded at about 11 a.m., the building rumbled, the lights flickered, and an automated voice over the public address system urged people to leave. Moments later, a man, coughing repeatedly, again urged people over the public address system to leave. When firefighters arrived at the three-alarm blaze, they quickly realized smoke was filling the stairwells and went on the public address system to urge people to remain in their offices.

By then, workers were already fleeing through the stairwell filled with smoke that smelled like burning rubber. Some panicked and wept, and covered their faces with hats and scarves.

About 800 people fled the 36-year-old, 301,000-square-foot building, which is owned by the Massachusetts Institute of Technology and houses small technology firms and some university offices.

David Clemens, 46, who was at work on a software program for Ascent Technology Inc. on the fifth floor, said that there was confusion after the blast because the instructions that came over the public address system "were wordy, and we really couldn't make out what they were trying to tell us."

With about 100 other people, he walked down one staircase, was pushed back by smoke, tried another staircase that was just as bad, and then went back to the first staircase and made his way down. He left through a main door in the lobby, he said.

Several workers credited John Culhane, a 41-year-old electrician who was working on the sixth floor, with helping them escape. Culhane used a ladder to smash a window and then helped workers climb to safety on the roof of the parking garage.

Samantha Huq, who was working at the New England Healthcare Institute on the 12th floor, was among those who escaped onto the adjacent garage. She said that when the fire alarms sounded, she believed it was a drill, until a building security guard told her office to evacuate before the public address announcement.

"There was a lot of rushing, people pushing," Huq said. "We got down to the third or fourth floor, and there was this thick gush of air coming up, and that's when people started to panic, because we didn't know how to evacuate. It smelled really bad, and it was really scary, because we started to think that we wouldn't get out alive. Some people were crying, and there was chaos."

Shelley MacAskill, 25, left her office on the 10th floor, made it to the sixth floor, and then escaped onto the garage. "People were freaking out," she said. "I got a lungful of smoke and got dizzy and thought I was going to pass out."

Cambridge Fire Chief Gerald R. Reardon said that when the transformer exploded, it ignited heavy wires and cables, which released the thick, black smoke. Someone who was trying to douse the fire left a basement door ajar, allowing the smoke to escape into the building, he said. The heating system, which was working to keep offices warm on a frigid day, carried the smoke up into the staircases, he said.

Reardon said it was not known what sparked the explosion in a secure room, known as "the vault," that houses electrical equipment. "We know they were doing maintenance and something went drastically wrong," he said.

NStar officials declined to comment on the cause of the explosion, but said they were cooperating with investigators, who include the Cambridge Fire Department and the US Occupational Safety and Health Administration. The emergency closed Memorial Drive and Longfellow Bridge, clogging traffic for several hours, and interrupted service on the MBTA's Red Line.

Outside the building, 28 ambulances lined the street, and emergency workers set up a triage station on the second floor of the nearby Marriott hotel. There at least 20 people at a time were on oxygen, Reardon said.

Workers who stayed outside shivered in the cold as a light snow fell. Some wore oxygen masks. Others used cellphones to tell family and friends they were all right.

About half the people taken to hospitals were treated at Beth Israel Deaconess Medical Center and the other half at Massachusetts General Hospital.

The workers did not have burns from breathing in the smoke, but doctors were worried about carbon monoxide, said Alasdair Conn, chief of emergency services at MGH.

Fidalgo was in cardiac arrest when he arrived at the hospital and died several minutes later.

Tom May, NStar's president and chief executive, praised the response to the explosion and called Fidalgo's death a tragedy. "Our thoughts at this time are with Kevin's family and helping them in any way we can," he said in a statement.

The Roxbury home where Fidalgo grew up, playing football on Clarence Street, was full of mourners yesterday afternoon, and screams of grief could be heard coming from an upstairs room. As relatives and friends crowded into the house, the Rev. Jose Alvaro of St. Patrick's Church said a prayer. Later, as additional mourners flowed into the house, several women carried coffee and doughnuts into the kitchen.

An only child, Fidalgo lived with his mother, Margarida , and his grandmother. Fidalgo served as an altar boy at St. Patrick's, a popular place of worship among area Cape Verdeans. He starred in football at Boston Latin High School and then went to the University of Massachusetts at Amherst, where he was a running back and majored in sociology.

Fidalgo did not drink or smoke and was a personal trainer at a gym, friends and family said.

Fidalgo loved to travel, his favorite destinations being Miami and Brazil. He recently bought a condominium in Dorchester, but would often return to Clarence Street to visit his mother and grandmother.

"He was a great guy, a hard worker who got along with everyone,"' said John F. Barros, his cousin and executive director of Dudley Street Neighborhood Initiative.

Michael Levenson and April Simpson of the Globe staff and Globe correspondent Andrew Ryan contributed to this report.