The man who fell off the roof is believed to have been visiting the member of the Class of 2013 when he sustained his injuries. The recent graduate, 22, is renting a room on the second floor of Sig Nu this summer but is not affiliated with the fraternity.
Hanover Police and Fire Departments arrived on the scene at around 6:15 p.m. and transported the victim to Dartmouth-Hitchcock Medical Center for treatment.
The man unaffiliated with Dartmouth, 20, was taken to DHMC for treatment related to his drug use.
Acting police chief Frank Moran said he was unsure if the individuals had been released from DHMC.
"I did get an update about the person who was seemingly in the worst condition, and he seems to be improving," Moran said.
He added that officials have a "working understanding" of the events.
The case remains under investigation by the Hanover Police, Safety and Security associate director Keiselim Montas said in an email.
No charges have been filed thus far. Police conducted interviews and executed eight search warrants following the incident.
Sig Nu summer president Blaze Joel '15 said that members are thankful that the individuals only suffered "minor injuries" after the fall.
No one affiliated with the house was involved in the activities that preceded the event or witnessed what happened, he said.
"We are unsure of the underlying facts surrounding this incident and are fully cooperating with the ongoing investigation," Joel said in a statement.
Police and Safety and Security cars lined Webster Avenue after the Hanover dispatch center received an emergency call at 5:53 p.m.
Two members of the Class of 2012 fell from the roof of Alpha Delta fraternity in June 2011. Both students suffered serious injuries and were transferred to DHMC.
College spokesperson Justin Anderson declined to comment. Safety and Security director Harry Kinne could not be reached for comment.
Joel is a member of The Dartmouth staff.
