A lawsuit filed by Sarah Short SOM ’13, who was injured in the fatal U-Haul crash at the 2011 Yale-Harvard tailgate, has been amended to include Sigma Phi Epsilon Fraternity Inc. as a defendant in addition to Brendan Ross ’13 and U-Haul.

Short filed a memorandum with the New Haven Superior Court on April 5, 2012, claiming she had suffered “severe and painful injuries” as a result of the crash, which killed a woman and injured two others including Short. Fourteen months after the incident, the lawsuit was amended on Jan. 28 to include Sig Ep as one of the defendants, as depositions indicated that Ross, the driver of the truck, was operating the vehicle on behalf of Yale’s chapter of the fraternity. Short is seeking at least $50,000 in damages from Ross, Sig Ep and U-Haul.

Ross was driving a U-Haul into the tailgate area assigned to Sig Ep before the Yale-Harvard football game on Nov. 19, 2011, when the vehicle accelerated and swerved into the Yale Bowl’s D-Lot around 9:39 a.m., killing 30-year-old Nancy Barry from Salem, Mass., and injuring Short and Harvard employee Elizabeth Dernbach. In a Feb. 1 hearing, Ross agreed to enter a probationary program that will allow him to maintain his record, with his charges revised to reckless driving and reckless endangerment.

Eric Smith, Short’s attorney, said the amendment to the suit follows “the basic principle of vicarious liability,” a legal rule that imposes liability on an organization or employer for an act, error or omission by one of its agents. In this case, Sig Ep is allegedly liable as Ross was driving the truck on behalf of the fraternity.

“The law is clear: When you’re acting as an agent for a principal, the principal can be held responsible for the negligence of the agent,” Smith said.

Witness depositions during the case confirmed that the truck had been rented by Sig Ep for a fraternity-sponsored event and operated within the scope of the fraternity, Smith said. After being provided with the information regarding the U-Haul tailgating crash roughly two months ago, Short’s attorney filed a request with the New Haven Superior Court on Jan. 14 to add Sig Ep as an additional defendant in the trial. Fourteen days later, the court granted the request.

Sigma Phi Epsilon is a national organization with nondistinct local chapters, Smith said, and the Yale chapter is not a separate entity from the national group. Will Kirkland ’14, president of the Yale chapter of Sig Ep, deferred comment to the national organization Monday.

Kathy Johnston, director of risk management for the Sigma Phi Epsilon national organization, declined to comment on behalf of the organization but said the fraternity has not been served a summons from the court. Multiple representatives of Sig Ep declined to provide contact information for the organization’s attorney.

Smith said that he was recently introduced to lawyers representing Sig Ep over phone. While no hearings have been held yet, the two parties have exchanged paperwork in preparation for litigation.

The fraternity could be held responsible for Ross’ actions in two cases: if Ross was acting as an agent on the organization’s behalf, or if the organization itself was negligent in creating unsafe circumstances or not following protocol, said Steven Ecker ’84, an attorney for the family of Nicholas Grass ’05 in a 2005 lawsuit against DKE following a 2003 car crash that killed four Yale students and injured five others on the way back to campus from a DKE event. In the Grass case, which is still ongoing, the lawsuit alleges the negligence of the organization.

Short’s case, which is not connected with the Grass case except that the two are based on the same legal principle, alleges Ross was acting as an agent of Sig Ep, Smith said. In such cases, a fraternity can be found to be responsible if the individual is shown to be acting on behalf of the fraternity or engaged in a fraternity activity, said Joshua Sheffer, a Greek organization and hazing lawyer.

Ross, who passed a field sobriety test at the scene of the crash, pleaded not guilty to misdemeanor charges of negligent homicide with a motor vehicle and reckless driving in September 2012. His charges were later revised to reckless driving and reckless endangerment under a plea deal, making him eligible for accelerated rehabilitation, a probationary program that offers first-time offenders a path to a clean record upon completion of probation without violation.

Immediately following the accident, the NHPD launched a forensics investigation, which concluded that Ross “applied no brakes [on the U-Haul] as he traveled through the crowd” and “failed to maintain control of his vehicle, and, instead, accelerated into a crowd of people.”

In addition to the lawsuit filed by Short, Ross still faces another civil lawsuit from Barry’s mother, Paula St. Pierre. The victim’s mother plans to file a suit after criminal proceedings conclude, according to Ralph Sbrogna, her Worcester, Mass.-based personal injury lawyer.