Who killed Tony Stark's parents?

Tony Stark's parents, Howard Stark and Maria Stark, were murdered by the Winter Soldier (Bucky Barnes) in Captain America: Civil War (2016). Here's a detailed look at how it happened:

The Murder:

• Date: The murder took place in 1991, when Tony Stark was in his early 20s.
• Location: Howard and Maria Stark were traveling to Russia when they were killed, and their deaths were staged to look like a car accident.
• The Killer: Bucky Barnes, also known as the Winter Soldier, was responsible for the murder. He was under the control of HYDRA at the time, who had brainwashed him into becoming an assassin.

The Truth Unveiled:

• In Captain America: Civil War, Tony Stark discovers the truth about his parents' deaths. Up until then, he believed that their deaths were a random act of violence.
• Steve Rogers (Captain America) reveals that Bucky, under the influence of HYDRA, was the one who killed Tony’s parents. This revelation occurs during a heated confrontation between Iron Man and Captain America.
• The discovery devastates Tony, as he grapples with the reality that his childhood friend, Bucky Barnes, was responsible for such a traumatic event in his life, even though Bucky was unaware of his actions at the time due to his brainwashing.

The Emotional Conflict:

• The revelation causes a major rift between Tony Stark and Steve Rogers, as Tony feels betrayed and is consumed by anger and revenge.
• The conflict between Tony and Steve intensifies, contributing significantly to the tensions of the Infinity Saga.

Why It Happened:

• HYDRA, the secret Nazi organization within S.H.I.E.L.D., was responsible for controlling Bucky Barnes and turning him into the Winter Soldier. They tasked him with the mission to assassinate Howard Stark and his wife, Maria, because they were working on the creation of the super soldier serum and were considered a threat to HYDRA's plans.

Impact on Tony Stark:

• Tony’s discovery of the truth about his parents' murder is a pivotal moment in the MCU, deeply affecting his relationship with Captain America and shaping his actions in the later films.
• The emotional trauma of his parents’ death, combined with the betrayal he felt upon learning who the killer really was, plays a key role in Tony’s decisions leading up to the Infinity War and Endgame events.

In short, Bucky Barnes, as the Winter Soldier, was the one who killed Tony Stark’s parents, under the manipulation of HYDRA, and the truth was revealed to Tony in Civil War, which profoundly impacted his character arc.