said more time was needed to consider her lawyers' last-ditch appeals, but the Supreme Court allowed the execution to proceed after a nine-hour delay.

The state's Republican governor declined to intervene and allow Pike to serve a life sentence.

Pike's  deeply disturbing' failed execution

After the state administered two doses of pentobarbital, witnesses said 50-year-old Pike was still alive and snoring.

Pike was taken to a hospital, where she has been unconscious ever since, her lawyers said.

Pike's attorneys said they believe problems with the IV lines caused the pentobarbital to flow into her body instead of her bloodstream.

 Apparently at no point did any member of the execution team realize that the IV lines were not correctly placed or that the veins had blown and that the pentobarbital was, in whole or in part, entering Ms. Pike's body,  they wrote in court documents.

Prisons chief resigns

Big picture view:

The stunning failure has left both sides of the death penalty debate demanding answers. Tennessee Gov. Bill Lee called it  deeply disturbing  and called for an independent investigation.

RELATED: Arizona's history of botched executions resurfaces after Tennessee lethal injection fails

On Saturday, Lee announced that Frank Strada, commissioner of the Department of Corrections, will resign this month.

In a statement to The Associated Press, Strada said his resignation is  in the best interest of Tennesseans  while the independent investigation moves forward.

Dig deeper:

This was the second time this year Tennessee has not been able to execute a prisoner who was seemingly moments away from death. In May, Tennessee stopped the execution of Tony Carruthers after staff placed an IV into his right arm but couldn't get a secondary IV line.

What's next for Pike's death penalty case?

What's next:

If Pike recovers, it is unclear what will happen in her death penalty case. Pike's lawyers have asked the governor to commute her punishment to a life sentence.