Assassination of Howard and Maria Stark

The Assassination of Howard and Maria Stark was a successful attempt by HYDRA to assassinate S.H.I.E.L.D. co-founder Howard Stark and gain access to the Super Soldier Serum.

Background
Following the end of World War II in May 1945, over 1,500 German scientists, engineers, and technicians were recruited by the United States in a classified effort known as "Operation Paperclip". Chief among them was former HYDRA scientist Arnim Zola, who joined S.H.I.E.L.D. in a clandestine attempt to rebuild HYDRA from inside the newly-founded peacekeeping organization.

Although Zola passed away from a terminal diagnosis in 1972, the new HYDRA continued to grow in power, orchestrating crises and sowing seeds of destruction.

In 1991, HYDRA learned that S.H.I.E.L.D. co-founder Howard Stark had recreated the Super Soldier Serum and tasked Vasily Karpov, a sleeper agent embedded in the Russian Armed Forces, with reviving the Winter Soldier. Karpov did as he was told, ordering the master assassin to retrieve the serum and leave no witnesses behind.

Assassination
"Help... my wife... help my wife. Sergeant Barnes?"

- Howard Stark's last words

On the night of December 16th, Stark and his wife Maria were en route to the Pentagon with the newly-completed serum when the Winter Soldier shot at their car, causing it to crash into a tree.

As the Winter Soldier approached the fallen vehicle, Stark crawled from the car and asked him to help Maria. He recognized the assassin as Bucky Barnes only to be repeatedly punched in the face and have his skull crushed by the Soldier's cybernetic arm.

After placing Stark's corpse back inside the car and strangling Maria to death, the Soldier proceeded to shoot at a nearby security camera before departing with the serum.

Aftermath
"I never got to say goodbye to my father."

- Tony Stark

The Starks' passing resulted in their orphaned son Tony being raised by Edwin Jarvis, who became a father figure to the young man.

The newspapers reported on the Starks's passing, but their deaths were attributed to a simple car accident.

HYDRA used the serum to give five individuals the same capabilities as the Winter Soldier, but they proved too dangerous to be sent into the field and remained in suspended animation at a facility in Siberia.

Years later, Helmut Zemo used footage of the event to manipulate Tony into fighting Steve Rogers and Bucky Barnes.

Appearances
In chronological order:
 * Captain America: Civil War (flashback)
 * Iron Man (mentioned as a car accident)
 * Iron Man 2 (mentioned as a car accident)
 * Captain America: The Winter Soldier (mentioned as an assassination by Winter Soldier; shown via HYDRA footage)
 * Captain America: Civil War (shown via HYDRA footage)