SEPTA clears Suburban Station about 12:30 a.m. daily for security reasons and to give cleaning crews time to prepare for the morning commute. The station offers a warm, relatively safe refuge for people, many suffering from mental illness or addiction, who have nowhere else to go. But the space can become dirty. There have been safety concerns, including a stabbing death and an accidental electrocution, in transit stations in the last two years. Drug use, particularly of K2, a synthetic compound sprayed on plant matter and smoked, is widespread.