An apparent miscommunication about a shop-fabricated section of a temporary hoist mast, in which the field crew assumed missing bolts were in place for final erection, was a key cause behind a tragic accident that killed a New Hampshire ironworker and seriously injured another worker last year, according to a report by federal safety officials obtained by ENR.

The accident took place June 11th, 2015, at an an office building jobsite in Somerville, Mass., where a contracting team was at work last year on the 13-story building. Crews were extending the masts on two, external side-by-side personnel and material hoists when one of the masts failed and the cab on it fell, killing one worker inside and seriously injuring another.

Ron Morse, 40, an ironworker foreman for Shiloh Steel Erectors, Raynham, Mass., was in the hoist cab when it fell from its position at the building’s third floor. He went into cardiac arrest and later died at Massachusetts General Hospital in Boston.

Mark Praetsch, 30, an apprentice employed by Liberty Equipment and Supply, Braintree, Mass., was also in the hoist cab and was seriously injured.

Another Liberty employee was struck by the mast or cab, which also narrowly missed Liberty’s assistant safety director, according to the OSHA report.

The Occupational Safety and Health Administration says it proposed penalties of $21,000 against each of the employers for allegedly failing to inspect the hoist components before installation, failing to adequately instruct employees about hoist safety and failing to follow and comply with the hoist’s manual. Liberty settled its penalty for the full amount and Shiloh settled for $13,500, OSHA stated.

A spokesman for the project’s general contractor, Boston-based Suffolk Construction Co., says that “since the time of this unfortunate and terrible incident,” the contractor has worked with OSHA and rewritten its hoist policies and job safety and hazard analysis programs. Suffolk also has provided training for Liberty employees and trade partners “who work with this equipment,” the spokesman said. “Our goal is to continue to reinforce our safety mindset in everything we do and to ensure that a similar accident never happens again.”

How the Accident Unfolded

The events leading to the accident, as described in the report, describe some of the alleged errors that lead to tragedy.

On June 11, 2105, the crews were preparing to add new sections to side-by-side hoists, with Morse and Praetsch in one of the hoists and a separate two-person crew employed by Liberty and Shiloh were in the other. 

According to the OSHA account, Morse and Praetsch were plumbing the mast sections for their hoist while the crane had the second mast brace on the hook preparing for welding to the structure.

Morse called out that he needed a laser level to plumb.

The crew in the other cab descended to get the laser level for Morse.

As the second hoist cab reached grade, the mast and hoist on the other side, with Morse and Praetsch inside, “collapsed to the ground,” the report stated.

The Mast’s Missing Bolts

The field crew had assumed the mast sections fabricated off-site at Liberty Equipment’s shop had all final connections and arrived ready to be rigged and put in place, the report states. But two bolts were missing from the mast section. The report doesn’t show the exact location of the bolts, but a photo with the report shows bolts at the end of one section that had sheared, presumably because the missing bolts were not in place.

According to the report, three different Liberty Equipment employees stated that “Liberty generally only assembles the mast sections at the shop for trucking purposes, and that it’s up to the field crew to disassemble all of the mast sections and re-bolt and torque the mast sections together utilizing new bolts and nuts.”

No extra bolts were found at the jobsite, partial confirmation that Liberty Equipment didn’t expect to complete preparation of the masts.

Liberty Equipment declined to comment on the OSHA report and officials of Shiloh Steel, which is a subsidiary of Suffolk Construction, could not be separately reached.

There is no information regarding lawsuits connected to the accident. Over a year later, Suffolk is readying the remaining unfinished floors of the new building, an administrative office for Partners Healthcare, for occupancy.

One Month After Accident

There was one last part to the OSHA report, which was first obtained and reported on in the Somerville Journal (ENR separately obtained the photographs).

About seven weeks after the accident, a complaint about work at the jobsite was phoned in to OSHA complaining that a hoist was being erected unsafely.

According to OSHA, the agency dispatched an inspector to the jobsite where he or she learned that Liberty Equipment intended to “jump” a mast section on the hoist at 3 p.m.

At the jobsite, the OSHA inspector “observed the mast sections and observed two bolts/nuts missing from one of the mast sections” that had been preassembled in Liberty Equipment’s shop.