Erik Lehnsherr (aka Magneto) and his then girlfriend Magda had suffered in the Nazi concentration camps during World War II. After they had knocked down a guard and stole his rifle the two of them fled the camp and, luckily, where not found by the Nazis.
After the war both Erik and Magda tried to turn over a new lief in their lives. They got married and had a daughter named Anya. Hoping to get a place at University, and through that giving his young family the best future they could get, Erik took his family to a larger city in the Ukraine. Although Anya saw the city as a site to behold, her father Erik fairly soon met with trouble. He accidentally and in frustration used his mutant powers (for the first time) on his boss at the place he worked. Although his boss wasn't hurt, or even touched for that matter, some people saw Erik as a thread to their community after this.
When Erik returned home from work the following night, he saw the house he and his family where staying in, ablaze (this was just an accidental fire). His wife Magda was already out of the house before the fire started, but Anya was still inside. Both parents ran into the building, trying to save their little girl. At that moment a supporting wall collapsed on the couple, but strangely they didn't have a scratch. Erik used his powers, again accidentally, generating a magnetic field around them to keep them from harm.
After he had taken Magda out of the building again, Erik wanted to go back to make one last attempt to save his daughter. At that moment though, two police officers grabbed him, and told him he was under arrest for assaulting his boss at the work place. Begging to release him so he could save his daughter, Erik's begging was met with a hit to the head and one of the officers telling him that nobody would risk their life for the daughter of someone who was obviously an enemy of the state.
Erik and Magda could do nothing more but hearing the screams of their daughter Anya as she died in the burning house. The rage over Anya's death awakened Erik's full mutant powers, killing everyone in the vicinity except for Magda. After the dust cleared Magda stood horrified after seeing the acts her husband just committed. She asked him what he had done. Erik just replied saying that they deserved nothing less, because they let Anya die. Magda replied saying that he was no longer the man she knew and loved, but a monster and she ran away. It was the last time Erik saw Magda. Magda, at the time, was pregnant of Erik again. She birthed two children, the mutants who would later become the world famous Quicksilver and Scarlet Witch. The fact that Erik had two more children was unknown to him until both Quicksilver and Scarlet Witch where already young adults.