Construction sites should reassess their fall prevention methods following the four recent fatalities resulting from people falling off buildings or scaffolding in southwestern Pennsylvania, a director for the U.S. Department of Labor's Occupational Safety and Health Administration said yesterday.

"One worker fall accident is unacceptable, but four falls within a few days' time is completely incomprehensible," said Robert Szymanski, the area director for OSHA's Pittsburgh office.

The most recent accident was Tuesday, when Roy Pfoertner, 53, of New Kensington, was working on the roof of the Pennsylvanian apartment building Downtown. He fell 13 stories to the sidewalk. He was part of a crew doing masonry work on the roof for the contractor, Mariani and Richards.

Three more construction-related deaths from falling have occurred within the past week. Carl Beck, 29, of Butler, fell 42 feet from a roof in North Strabane, Washington County, on Saturday morning. On Friday morning, Gary E. Dwire, 56, fell from a house in New Kensington, and Michael Grinder, 40, fell two stories at a site in Monessen.

Historically, fatalities in the workplace have been on the decline in recent years, and Mr. Szymanski said last week his office was projecting that they might achieve a single-digit record low for fatalities for the fiscal year, which ends Sept. 30. But the four fatalities since Friday bring the total to 11 workplace fatalities for this year.

In the construction industry nationally, falls account for nearly 50 percent of all fatalities, Mr. Szymanski said.

"If you eliminate fall hazards in construction, you would eliminate 50 percent of fatalities right off the bat," he said.

Of course, the goal is to have zero fatalities in the workplace every year, he said.

To achieve this goal, OSHA mandates safety requirements that protect against hazards like falling. Employers are required to protect their workers from falls when they are working six feet or higher above an adjacent surface by one of three methods -- a guardrail system, a personal fall arrest system like a body harness and line or a safety net.

There is an entire book of OSHA standards related to construction, but Mr. Szymanski emphasized these three methods of fall protection as imperative.

"I'm asking that employers take time to pause and assess their work sites immediately for appropriate fall protection systems," he said.

OSHA conducts regular inspections of workplaces to verify they are complying with the standards. The agency investigates all workplace deaths, and have started investigations for the four fatalities, including the one that occurred Tuesday.

If violations of OSHA standards are identified through the investigations, penalties may be assessed according to the circumstances, Mr. Szymanski said. These can include fines and recommendations to minimize risk.