The accidents that have killed two New Jersey construction workers and crippled a third in Pennsylvania  in the past year typify the mundane errors and oversights that often lead to tragedy.

Early on Feb. 18 in Whippany, N.J., for example, crews working on a new firehouse were using a crane to lower a five-ton generator to a concrete pad at ground level. The generator broke free of the rigging and struck two workers, killing one and trapping a second beneath it. That worker was rescued but died later from his injuries.

Few details could be confirmed. Hanover Township Mayor Ronald F. Francioli told the Daily Record, a local newspaper, that he was called about the accident around 11 a.m., and that the accident involved a broken strap. The Philadelphia office of the U.S. Occupational Safety and Health Administration did not release the names of the workers that were killed and the employers identified by OSHA could not be reached for comment.

Meanwhile, the Philadelphia OSHA office says it has reached settlements with contractors over an accident last year in West Chester, Pa., in which which an employee was severely injured in a fall.

On July 6, 2015, a forklift fitted with a makeshift platform raised a 30-year-old construction worker to the roof level of new condominium apartments. The worker was installing gutters when the platform toppled and the worker fell 40 feet, suffering serious injuries,including paralysis from the waist down.

OSHA, in its citations against several companies, claimed that High Quality Builders Inc., Bordentown, N.J., regularly misused rolling equipment to support work platforms, failed to properly train workers to recognize fall hazards and failed to provide fall protection. These and other alleged violations prompted OSHA to issue citations for eight serious and two repeat violations, with $72,880 in penalties. According to OSHA, the agency cited High Quality Builders for similar violations last March and June. High Quality Builders could be reached for comment and a message left for the company owner was not returned.

This article was corrected Feb. 24 to reflect the fact that the recent accident involving the generator took place in Whippany, N.J., and not in Pennsylvania.