Elfrieda Grace Knaak was an American schoolteacher whose death became a big news story.

She was born on September 21, 1898, in Deerfield, Illinois, to Theodore Ludwig Knaak and Elise Knaak (born Becker). Both of her parents were born in Germany and moved to the United States. They married in Illinois in 1873. Elfrieda was the youngest of nine children: five brothers named Theodore, Edward, Otto, Alvin, and Rudolph, and three sisters named Emilie, Ida, and Amanda. She attended Deerfield-Shields High School, completed a college program at Michigan’s state normal school, and studied for one year at the University of Illinois and two years at the University of Chicago. She worked as a schoolteacher and a Sunday School teacher in Deerfield and Waukegan, and as a sales agent for Chicago’s Compton Book Company’s encyclopedias. She was one of the first members and an assistant leader of the Deerfield chapter of the Masonic Order of the Eastern Star, which was started at the home of her sister Emilie on June 5, 1924. Her sudden and mysterious death by fire in 1928 became a major news story.

Death

Elfrieda Knaak died on November 2, 1928, in Lake Forest, Illinois, at the age of 30. She is buried in Deerfield Cemetery.

At 7:30 a.m. on Tuesday, October 30, 1928, Elfrieda was found in the furnace room of the Lake Bluff village hall. She was unclothed and had severe burns on her hands, feet, head, neck, and face. Doctors later said she was burned shortly before 7:00 a.m. that morning. She was discovered by Chris Louis, a street employee and janitor, who had gone to refill the fire. Her purse, wrist watch, and shoes were found on the floor of her basement, and burned pieces of her clothing were found in the furnace. Her heavy coat was not found. Louis called Village Marshal Barney Rosenhagen, policeman Eugene Spaid, and Dr. A.J. Rissinger. Police Chief Rosenhagen said he had checked and locked up the station at 9:00 p.m. the night before and had gone home. A telephone operator reported that a woman had called the station at 9:30 p.m.

Elfrieda was responsive when she was taken to the hospital by ambulance but refused to explain how or why she was in the basement or how she had been burned to Officer Spaid, who rode with her. Later, she told investigators she entered the building through a rear door and discovered she had been locked in, leading police to believe she had already entered the building before Rosenhagen locked it at 9:00 p.m. Elfrieda told Dr. A.J. Rissinger and Dr. T.S. Proxmire that she did not feel pain and believed she would recover. The Chicago Tribune quoted her as saying, "I did it myself. No one was with me. I did it for purity, for love." She died at Alice Home Hospital in Lake Forest at 4:00 a.m. three days later, on Friday, November 2, 1928. A reporter present at her death said she muttered, "I wonder why they did it," and when asked who, she said, "I don't remember." Physicians at the time said her story suggested "an acute nervous disorder." They also believed she was "suffering from dementia praecox when she braved the fire." Her funeral was held on Monday, November 5, 1928.

Coroner John L. Taylor found signs of electrocution and a severe blow to the head, in addition to her burns. Lake County coroner’s physician C.A. Barnes said she "had not been attacked nor beaten." The investigation was conducted by State Attorney A.V. Smith, Sheriff Doolittle, and Chicago’s Hargraves Detective Agency, led by George Hargrave. One of Elfrieda’s brothers said she told him she burned herself to prove the power of mind over matter. Two false confessions were made: one by an Army deserter, Ezra MacVeagh, who used the name James Kelley, and one by an anonymous letter from someone claiming to be a student of the occult. Both confessions were contradicted by evidence. MacVeagh had been in a state asylum in Elgin, Illinois, at the time.

Speculation arose about Elfrieda’s relationship with Charles Webster Hitchcock, a 45-year-old married father of four and night officer who also taught salesmanship, public speaking, and expression at the Waukegan Y.W.C.A. Hitchcock had previously been an actor with Essanay Studios and later a vaudeville performer. Elfrieda had studied salesmanship with Hitchcock at the Y.W.C.A. four years earlier and had visited the police station "every two or three months to report on the progress she was making," according to Hitchcock. Elfrieda’s story suggested a romantic attachment to Hitchcock; she described him as her "spiritual sweetheart" and told doctors her burning was "because of her faith in God and as a test of her love for a handsome married man." On Thursday, November 1, Dr. Rissinger reported her statement, "we did it," which he interpreted as meaning herself and a "spirit." When State Attorney Smith suggested arresting Hitchcock, Elfrieda reportedly said, "You would be doing a rank injustice." Hitchcock had been home with a fractured ankle from a car accident for two weeks at the time of her burning, as reported by two witnesses. Hitchcock himself said he did not believe she could have acted alone, stating, "The investigation on this thing ought to be pushed to the limit. It's preposterous to think that she could have done it herself." Dr. Rissinger later said Elfrieda initially told him she had probably been burning herself all night as she fainted and fell several times, and that she loved Policeman Hitchcock but had only talked with him "spiritually." Rissinger also reported that Elfrieda said Hitchcock "got her out of hell three months ago," but she did not explain what she meant. She occasionally mentioned Hitchcock going back to his wife or his wife going back to him. Hitchcock’s wife, Estelle Hitchcock (née Bacon), testified she knew nothing about Elfrieda’s attachment to the policeman and had been working during the evening Elfrieda was burned.

An inquest was held on Saturday, November 10, 1928, in which a Lake County coroner’s jury concluded that Knaak "came to her death 'by burns which appear to be self-inflicted.'" The coroner’s jury included six men from Lake Forest: A. Duane Jackman, John Kreutzberg, George Anderson, H. L. Hamer, Thomas L. Eastwood, and J. E. Fitzgerald. Despite the jury’s conclusion, State Attorney A.V. Smith decided to keep detectives on the case. On Thursday, December 6, 1928, Elfrieda’s brother, Alvin Knaak, announced that a special investigation, funded by the Knaak family and county authorities, was underway. He said, "We believe Elfrieda may have burned herself, but the results of our investigation thus far lead us to believe that a moral responsibility for her action rests on others. We are hoping to discover what happened between 9:45 p.m. and midnight the night of her accident, and we are making some headway." Her sister, Emily, said, "It is simply impossible that she could have done such a thing—physically impossible. What happened, or how, we have no idea. We know only that she must have been slugged, or more likely drugged, and that her mind

Public reaction

The Chicago Tribune reported that groups of people who were curious and wanted to see visited the Lake Bluff village hall on Sunday, November 4th, 1928. However, they were not allowed to enter the basement where Elfrieda died in a fire. In the two days after her body was found by Chris Louis, the Chicago Tribune published photographs of Elfrieda Knaak, Charles W. Hitchcock, Officer Eugene Spaid examining her purse and shoes near the furnace, and the furnace door, which was 12.75 inches wide and 8.75 inches tall. After Elfrieda’s death, her family read her letters and diary, and some of these were shared with the public. Her brother, Alvin, shared a diary entry that read: "Oct. 10. Went this afternoon without any sale. Called H. at 6 P.M. He said it seemed like three weeks and hoped I would come soon."

On Saturday, November 10th, an inquest into Elfrieda’s death lasted from 9:00 a.m. to 5:00 p.m. Around thirty people gave testimony, and many people came to watch, with more than 200 in the courtroom most of the time. On Friday, November 16th, The Lake Forester reported that a "clue" was found in a letter written in a feminine hand, signed "B. Lock," and sent from Libertyville. The letter used kind words and suggested that the writer and Elfrieda had a close, friendly relationship, but that Elfrieda later became distant.

The Chicago Tribune later reported that Elfrieda had met a woman named "B. Lock" three weeks earlier while working in Libertyville. Elfrieda first visited as a book sales agent, but later met for meals and religious discussions, and they made several long-distance phone calls. At some point, they had a disagreement, and "B. Lock" wrote in a letter that Elfrieda was "forgiven but would be sorry." "B. Lock" was later identified as Mrs. Luella Roeh, wife of H.P. Roeh, a contractor in Libertyville. Luella said in an interview, "Fritzie came to my house to sell books on Sept. 20. She seemed to like me. After her second visit, I became aware of a certain power she had over me. I liked her, too, but I felt like I was being hypnotized in a way." Luella also said Elfrieda told her, "I am not here with you… I am in another world entirely—a spirit world."

A Tuesday, November 13th, story in the Chicago Tribune included a quote from a book Elfrieda had annotated, Christ in You, written by an unknown author and first published by Dodd, Mead & Co in 1916: "As you grow closer to understanding God, many confusing things become clearer. One is the purifying process of pain. It is safer and grander to suffer, because, rightly viewed, it is sure to perfect the soul. Have you not sometimes felt the shallowness and the emptiness of joy? …This is the process called 'the refiner's fire.'" Additional letters and parts of Elfrieda’s diary were published the week of Monday, December 3rd, in multiple Chicago newspapers.

Legacy

Less than a month after Elfrieda's fire, on November 27, 1928, the city council removed Chief of Police Bernard "Barney" Rosenhagen from his position. He was given six months of time off from his other jobs, which included working as superintendent of the water works, head of the street department, and poundmaster. The council stated that Rosenhagen had heart disease and "was not able to care for his duties." Officer Spaid took over as chief. At the same time, the city council's police committee asked Night Officer Charles W. Hitchcock to resign. Just weeks later, on Monday, December 17, 1928, Rosenhagen died at home at the age of 62. His death was linked to heart disease, but the doctor who treated him said "criticism following the Knaak case probably had hastened his death." Less than a year later, initial suspect Charles W. Hitchcock (then working as a bill collector) and his 18-year-old son Raymond were arrested for burglaries in Lake Bluff.

The case remained in people's memories. A London Chicago Tribune reporter compared a woman's death by fire in 1954 to Elfrieda's death in 1928. In 2016, a Chicago Tribune article by Ron Grossman titled "Who Really Killed Elfrieda Knaak?" revisited the case's details and other suspects. In July 2018, a fictionalized version of the case by Kraid Moreland and Toby Jones was published, titled The Furnace Girl: The Mysterious Case of Elfrieda Knaak. In February 2019, Chicago's WGN9 aired a podcast by Larry Potash about Elfrieda Knaak's death. In 2024, the podcast Crime Junkie released an episode titled "Mysterious death of: Elfrieda Knaak."