Jeffrey Epstein , the multmillionaire financier charged with sex trafficking dozens of underage girls as young as 14, reportedly died by suicide at the Metropolitan Correctional Center in Manhattan while awaiting trial.

The 66-year-old registered sex offender was part of an elite social circle and spent more than a decade evading federal criminal charges for his litany of alleged crimes. Had he been convicted, he could have faced up to 45 years in prison.

His death raises serious questions that must be answered, U.S. Attorney General William Barr said in a statement Saturday.

Epstein was found unconscious following a suspected suicide attempt just last month in his jail cell at MCC, which is operated by the Justice Departments Federal Bureau of Prisons. But he wasnt on suicide watch when he died, according to several news outlets, leading many people to wonder how such a high-profile inmate with a recent history of possible self-inflicted harm could be left unsurveilled in federal custody.

Conspiracy theories about alternate causes of death are already circulating on social media, and the FBI has opened an investigation.

Jail suicides are almost entirely preventable, a HuffPost investigation found in 2016, and theyre far more common than you might think: Suicide has been the most common cause of jail deaths for every year dating back to 2000. The number of detainee suicides hit a record high with an average of more than one per day in 2014, the year for which the most recent Justice Department data is available. Three-hundred and seventy-two people killed themselves, accounting for more than a third of all inmate deaths that year, according to the latest Bureau of Justice Statistics report on mortality in local jails. It was a 13% increase from suicide deaths in 2013.

Inmates face a greater risk of harm when jail authorities neglect to follow protocol. Those with a history of serious mental health issues or suicidal behavior need to be under continuous supervision, experts told HuffPost , as it can take just five minutes to die by strangulation, for example.

Under the circumstances, I would have a staff member sitting there or have a camera on [Epstein] 24/7 while he was in my custody, purely to cover my butt, Bob Hood, a former federal Bureau of Prisons chief of internal affairs, told NBC . I know that sounds tacky, but this is not your average inmate.

Not only had Epstein seemingly already attempted to take his own life, but he was also due to stand trial for federal criminal sex charges. Accused sex offenders are at a significantly higher risk of suicide than members of the general population.