Elected officials are scoring the city for a lack of oversight concerning safety issues at construction sites after a window installer plummeted nine floors to his death yesterday at a luxury development on the Upper East Side. Kevin Kelly, 25, of Queens was installing a window on the 23rd floor of the Laurel, a luxury condominium on First Avenue scheduled to open this fall, when he fell at about 10:30 a.m. and a safety harness he was wearing failed, officials said.

“What makes this so tragic is it could have been prevented,” Rep. Carolyn Maloney, a Democrat of Manhattan and Queens, said.

Kelly’s body was found on a 14th floor balcony at the northeast corner of the building at 400 E. 67th St., police said.

The Laurel, a development that will have training facilities for triathletes, has accumulated 25 safety violations since construction began in April, including several for failure to safeguard public property and failure to have a safety manager on site, an official with the New York City Department of Buildings said. A majority of the violations were marked class A, a designation the department uses for the most egregious violations, according to the department’s Web site.

“This is the third fatal construction accident this year within one mile on the East Side of Manhattan,” a City Council member who represents parts of the Upper East Side, Jessica Lappin, said. “The real question here is whether the buildings department is doing its job.”

Over the last two years, there have been 30 construction-related deaths in the city, the president of Manhattan, Scott Stringer, said.

Following the accident, a stop-work order was placed on the building and the buildings department announced that an investigation is under way to determine how the safety harness, which was one of several hanging from the ceiling of the 23rd floor, failed to prevent Kelly from falling, officials said.

“A tragedy happened here today,” the commissioner of the department, Patricia Lancaster, said in a statement. “We will pursue the toughest enforcement to the full extent of the law. Development cannot be at the expense of the workers building our City.”

Of the safety violations, none were for failure to maintain the safety straps, which construction workers are required to wear when operating within 6 feet of a ledge on an unenclosed floor, a buildings department official said.

The developer of the condominium, Alexico Group, released a statement following the accident, sending its deepest sympathies to Kelly’s family and showing support for the construction company, Hunter Roberts Construction Group.

“Construction safety is our utmost concern and we believe that the construction manager, Hunter Roberts, has a good safety record. We will cooperate fully with the City’s investigation of this tragic event,” the statement said.

Messages left with Hunter Roberts were not returned.

Even though a number of elected officials were up in arms over the number of “open” safety violations at the site, a buildings department official said 24 of the 25 safety violations had been remedied.

The president of the Real Estate Board of New York, Steven Spinola, said it could take more than a year for some violations to be cleared even if a developer has cured the problem.

Still, Mr. Stringer said there is no excuse for the buildings department’s inability to keep construction sites safe considering that the department has recently more than doubled its number of inspectors.

Construction workers at the site, who were told not to speak with the press about details of the accident, were visibly upset over Kelly’s death.

“He was a really good guy, a sweet-hearted person who did everything right,” a co-worker said.