When the prison warden asked Christa Pike if she had any last words, she said she was going to leave this world “with love” for those on her side and also the ones angry with her.

What followed was the second botched execution in Tennessee this year, after two doses of the lethal injection failed to produce the desired effect.

Witnesses present in the chamber said Pike was still breathing despite the injections intended to kill her late on Wednesday, that nothing about the failed execution was normal and that it was unprecedented. For their part, officials said they followed every step of the approved protocol.

Pike was finally taken to the hospital after surviving the two attempts to execute her. The current status of the woman convicted of murdering a classmate in 1995 is unknown. John North, an investigative producer at WBIR television in Knoxville and also a witness at the Riverbend maximum security institution in Nashville, said when he left the building she was “probably still alive”.

“This event is the worst we’ve seen and unlike any other botched execution in the modern era. There is no precedent,” said Robin Maher, the executive director of the Death Penalty Information Center, according to the New York Times.

“Nothing about today was normal, typical, at all,” said Tori Gessner, a reporter and anchor at WKRN of Nashville and one of the members of the media who served as witnesses in the execution, according to NBC.

“They went through two rounds, and she was still breathing at the end. She was very ragged,” said Catherine Sweeney, a reporter at the Nashville Public Radio WPLN, at a news conference after the execution attempt. “She lifted her head up and was looking around. At one point, she said … there was a spot that was burning and hurting, and asked if that was normal. None of it was normal.”

Gessner also said Pike was heard saying: “My arm feels like it’s about to burst open. Does this happen like that?”

Gessner described the victim as “inconsistently going in and out of snores and silence” after the injections. “When the curtains closed the final time at 8.05, we could consistently hear her snoring, and then it kind of developed into a snore squeak, and then a snore. And even at 8.53, when the microphone was cut off, we could still hear snoring.”

Pike, 50, was convicted of killing Colleen Slemmer, her 19-year-old classmate at Knoxville Job Corps. She had been scheduled for execution on Wednesday and would have been the first woman executed in Tennessee in more than 200 years. An appeals court stopped the lethal injection just an hour before it was to start, but hours later the US supreme court overturned that stay.

Slemmer’s mother, May Martinez, described the failed execution attempt in a phone interview with NBC News on Thursday. “It was a mess,” she said. The Tennessee governor, Bill Lee, said he was suspending all executions this year and ordered “a comprehensive, third-party review to determine exactly what occurred”.

In a statement, the department of correction said the state “followed every step of the State’s lawful, established execution protocol approved by the Attorney General’s Office” and that “the lethal injection chemical in the protocol has consistently been effective.” In May, Tennessee also aborted attempts to execute a man convicted of murders after failing to find a suitable vein for his lethal injection.