Every time Catherine Knot hears the scream of fire engines outside her window she shudders and the tension mounts. She's afraid that her building might be their destination, she says, and that this time she might not be so lucky.

Yesterday, she and more than 20 others were trapped on their fifth-floor balconies by a two-alarm fire that struck the Clifton Terrace apartments, 1350 Clifton St. NW, shortly before 3 a.m.

Officials said 83 firefighters battled the flames that began in the fifth-floor hall, trapping occupants and forcing them onto balconies where firemen used ladders and a cherry picker to evacuate them.

Fifth-floor resident Minnie Gaines did not have a balcony in her apartment. She and her 3-week-old daughter were trapped in her bedroom until firefighters could help them outside. The baby was later treated at Children's Hospital and released. In all, seven residents were treated for smoke inhalation.

According to fire spokesman Ray Alfred, the fire, now ruled arson, was caused by a flammable liquid that had been poured on the hallway floor and ignited. Investigators estimated damage at $35,000.

Knot said the fire was the fourth on her floor in recent months. The building's maintenance coordinator, Bobby Summerville, said he could recall only one recent fire on Knot's floor -- a blaze about a month ago that burned one apartment -- but added that there have been several trash fires at the complex.

Robert Walton, supervisor for Phoenix Management, the company that manages the complex, said tenants would be moved from three or four units damaged by the fire.

The 285-unit, low-income housing complex, built in 1916 as a luxury apartment house, is today deteriorated and described as crime-ridden, though the current owners are credited with some improvements.