Investigators are probing the cause of a fatal construction accident — the third in the city so far this year — that took place yesterday at the site of a luxury residential tower being built in Brooklyn. Preliminary investigations indicated that high winds caused pipe scaffolding to collapse underneath three laborers who were performing exterior stucco-work on the rooftop bulkhead at 525 Clinton Ave., a 13-story predominantly glass tower under construction in the Fort Greene section of Brooklyn, a spokeswoman for the New York City Department of Buildings, Kate Lindquist, said. A laborer who was atop the scaffolding, Jose Palacios, 43, fell to the ground and was pronounced dead at the scene at about 10 a.m., police officials said.

The accident, in which a second man was seriously injured, marks the third construction-related fatality in the city this year. In all of 2007, there were 12 deaths related to construction accidents.

Since another fatal accident earlier this month at the site of Donald Trump’s SoHo building on Spring Street, where a concrete worker plummeted from atop the building to his death, the buildings department has been investigating if faulty scaffolding may have caused the accident.

In the case of 525 Clinton Ave., a project of David Weiss and Jonathan Jacobs, who have collaborated on several other luxury residential projects in Brooklyn, investigators are looking into whether the scaffolding was properly secured to the building.

Prior to the accident, the buildings department alerted property owners and contractors across the city to secure their buildings because of predicted wind gusts of up to 50 mph, a warning the department sends out anytime the National Weather Service forecasts inclement weather conditions.

While buildings department inspectors issued the contractor of the project, Clinton Court Development LLC, six safety violations in November 2006, including one for failure to maintain a water source for firefighters, none of the violations were related to scaffolding.

However, the buildings department is investigating if the contractor and a subcontractor, Bell Tower Enterprises, which had hired the victims of the accident, had the proper scaffolding permits, a department official said. A spokeswoman for the Department of Investigation, Diane Struzzi, said the agency was aware of the incident but would not comment if it plans to conduct a criminal investigation.

A receptionist at Weiss and Co., an accounting firm that shares an address with Clinton Court Development LLC, said Mr. Weiss would likely not be commenting on the accident before the end of the day.