Louis Slotin was a Canadian nuclear physicist who played an important role in Manhattan Project during World War II. The Manhattan Project led to the production of the first nuclear weapons. Slotin died tragically after being exposed to radiation. He was born to Jewish immigrant parents in Winnipeg. A brilliant student throughout his academic life, he won many medals including a prize for his Ph.D. thesis. For a few years, Slotin worked at the University of Chicago. There he was part of the team that designed a cyclotron. He also contributed to the field of biochemistry by demonstrating how plant cells used carbon dioxide. He was soon picked up for the Manhattan Project where he gained a reputation for his ability to put together bombs. He was also known for being a master in handling dangerous radioactive material. During a demonstration of an experiment, an accident caused two radioactive materials to come in contact with each other setting off a chain reaction. Though the contact was brief it was lethal. Slotin had been standing too close to the radioactive material and the best medical care could not save him from the effects of radioactivity. After his death, the radioactive plutonium core that he was handling came to be known as ‘demon core’.