A Purdue University student was found dead in his off-campus apartment this weekend, the fourth student death to hit the campus in the last four weeks.

Police found Travis R. Simpson in his bedroom after a roommate called 911 when he found Simpson unresponsive at 4:25 p.m. Saturday, Feb. 3, said West Lafayette Police Chief Michael Francis.

The death is under investigation, and police would not comment on the circumstances surrounding the death. Typically in cases where the cause of death is not obvious and appears to be other than natural causes, police await the results of an autopsy before commenting on the case. The Tippecanoe County coroner’s office did not return several phone calls.

Simpson, from Kokomo, Ind., was a sophomore majoring in mechanical engineering technology and is the fourth Purdue student to die in two weeks.

Matthew T. Cahill and Jacob C. Cushman died on Jan. 26 after the car they were riding in lost control on a patch of ice and collided with a semi-truck. Police found Laura Marie Williams dead in her off-campus apartment Jan. 22, two days after she celebrated her 21st birthday. William’s cause of death is unknown pending toxicology reports that have not yet been returned to the coroner’s office.

“It is extremely unusual,” said Joseph Bennett, vice president for University relations, noting that all the deaths are unrelated.

University records show that over the last 20 years between eight and 10 students die a year on average at the Purdue campus, but the heavy concentration over the last four weeks stands out, Bennett said.