The first clang of the alarm came as many residents of the modern high-rise in Hell’s Kitchen, Manhattan, were sitting down to brunch or opening the Sunday paper. Quickly came the screams — “Fire!”— and an acrid smoke that blackened windows and seeped under doors and through air vents. Few knew exactly where in the 42-story building the fire was. Some tried and failed to reach 911 operators, who were overwhelmed by calls. Many decided to flee.

Daniel McClung was one of them. He and his husband, Michael Cohen, scooped up their two dogs and left their 38th-floor apartment. They reached only the 31st floor before they were overcome by smoke, fire officials said. Mr. McClung, a 27-year-old playwright, died. As of Monday, Mr. Cohen, 32, an online video producer, remained in intensive care at NewYork-Presbyterian/Weill Cornell hospital. Their two dogs, Schooner and Georgia, also died.

It is a basic human instinct reinforced by countless grade-school fire drills: When you see flames or smell smoke, get out. In New York, where the reminders of the Sept. 11 terrorist attack are omnipresent, the fates of those who waited and became trapped in the burning towers serve as a lesson for many, not least the people who live in high-rises like the Strand, the site of the Jan. 5 fire that killed Mr. McClung. But in modern high-rise buildings, fire safety experts say, flight can be deadly.

As they raced down the stairs, the couple ran into a suffocating plume of smoke sucked upward as if through a chimney when firefighters opened the stairwell door and pushed into the burning apartment.