D.C. Fire Department officials showed off their shiny, state-of-the-art ladder truck yesterday amid complaints by firefighters that the huge truck is impractical and will not fit down many narrow District streets.

During a morning news conference kicking off fire prevention week, fire authorities also announced that 10 people died in Washington fires during the last 12 months, the lowest number in 50 years.

Thirty-nine people were killed in the previous 12 months by District fires.

Officials said that part of the credit for the low number of fire fatalities goes to the department's smoke detector give-away campaign.

"If we are successful in the coming years, we hope to reduce that number to zero," said Assistant Fire Chief H.A. Clark.

He said the department has increased its budget for fire prevention programs by more than $1 million, expanded its community relations unit and added $4 million in equipment.

While officials praised the ability of the new ladder truck yesterday, a firefighters union official complained that the truck -- to be assigned to a Southeast firehouse -- could actually increase response time because of the difficulty of maneuvering it on some streets in that area.

"I feel that I have a moral obligation to inform you that locating a vehicle as large as the unit in question in Ward 8 seriously diminishes the rapid response and maneuverability that is presently enjoyed by the residents of Ward 8 through the fire service of the smaller unit presently in service," Tom Tippett, president of Local 36 of the International Association of Fire Fighters, wrote last week to D.C. Council member Wilhelmina J. Rolark (D-Ward 8).

Tippett said yesterday the "aerial platform" truck "will have trouble getting into some of the streets, much less alleys" and that the large trucks are better suited for suburban counties and downtown areas with "big, wide streets and avenues."

"No doubt it has advantages in the proper setting," Tippett said. "But if you can't get it up the street of the fire, what good is it?"

The truck's 102-foot ladder has an aerial platform "bucket" where five individuals can be placed until they either climb down the ladder or are lowered to the ground. The traditional hook and ladder truck has no platform.

"This is the best ladder truck made today," said Deputy Fire Chief James Tate. "The guys have just got to get used to it. After a while, they'll stop complaining about it." The District has purchased two aerial platform trucks for about $446,000 each, nearly the same cost of traditional ladder trucks.

One of the new trucks apparently was ordered for a firehouse at 3203 Martin Luther King Jr. Ave. SE, firefighters said.

But the truck has to be moved to the fire station at First Street and Atlantic Avenue SE at the edge of the District line because officials discovered the truck could not fit through the station doors, Tippett said.

Fire officials allowed reporters to be lifted up in the new truck's ladder platform, but refused to drive the truck down Newton Street NW, a narrow street alongside the firehouse.

Tate said he didn't know of any fire trucks that didn't fit into fire stations. "It hasn't been proven" that they couldn't get the trucks in, he said.

However, the firefighters union said this is not the first time the District bought fire trucks that were too big for city streets. In January, the city purchased a ladder truck seven feet smaller than the aerial platform model but larger than the traditional truck used by District firefighters.

It was originally assigned to a firehouse in Georgetown but was moved to a station across the city when it was discovered that the truck was too big for the Georgetown firehouse.