Hayes+Associates, Inc, Testimony Contributes to Plaintiff Verdict in Construction Site Trip and Fall Case

Clark v Pacific Image Melissa.jpg

Failure to adhere to globally recognized construction site safety protocols, codes and regulations can put workers at risk of falls and serious injury. 

In August 2009, Nathan Clark, a 29-year-old security guard for Salk Institute in La Jolla, CA, was directing first responders to a shipping/receiving area crime scene to tend a woman who had been stabbed.  Mr. Clark tripped over raised metal plates that were covering an underground construction site and had been baking in the hot sun for hours.  The plates were placed there by Pacific Rim Mechanical Contractors, Inc, in such a way as to create an overhanging lip as much as 2” in height.  In some areas, the plate edges were surrounded by sloped berms, as per ASTM safety standards—(ASTM International is a worldwide standards organization that publishes safety guidelines for a wide range of systems and services)—but the area where Mr. Clark tripped had no berm. 

As he attempted to recover from his trip and arrest his fall, Mr. Clark “felt something break in his hip.” He fell to the ground, suffering first and second degree burns on his left side from the hot metal plate.  Examination revealed sciatic nerve injury, and a serious fracture to his right hip.

Mr. Clark sought representation by Mr. Ljubisa "LJ" Kostic  of Estey Bomberger LLP, San Diego, (https://www.ebtrialattorneys.com/). Subsequently, the firm retained Hayes+Associates, Inc, to perform a biomechanical reconstruction of the incident.

A team at H+A analyzed Mr. Clark’s fall based on measurements at the site, ASTM standards, and established dynamics of the tripping human form.

As per ASTM protocols, changes in level greater than 1⁄2” must be protected by means of properly sloped transition such as a berm.

The Pacific Rim Mechanical construction documents also indicated that the plates should be surrounded by a berm. Thus, the scene of Mr. Clark’s fall did not even conform to Pacific Rim’s own design plans.

The H+A report concluded that a sloped ramp or berm leading to the edge of the cover plate would have prevented the incident and that the trip hazard created by the unsecured raised cover plates was the direct cause of Mr. Clark’s fall.

Wilson C. “Toby” Hayes, PhD, testified to this effect at trial and the jury found for Mr. Clark, awarding him damages in an amount that was not disclosed. 


Hayes+Associates, Inc. (http://www.hayesassoc.com) is an expert witness and consulting firm, based in Corvallis, OR. The company brings more than 75 years of collective experience in academic research, university teaching and forensic testimony to practice areas that include vehicle collisions, premises safety, slips and falls, products liability, worker safety, sports and recreation, patent litigation and criminal matters.