In the first scene of Ant-Man, we see Howard Stark alive and healthy in 1989. So, when did he die? And how? Is the answer different in different timelines?
Note: This is not a spoiler because you see it in the first few minutes of the movie.
In the first scene of Ant-Man, we see Howard Stark alive and healthy in 1989. So, when did he die? And how? Is the answer different in different timelines?
Note: This is not a spoiler because you see it in the first few minutes of the movie.
Howard and Maria Stark were killed in an automobile “accident” secretly arranged by HYDRA on Long Island in 1991, to remove him as an obstacle in their plans.
Here is the Youtube clip from Captain America 2 to prove that and following is the screenshot:

After Captain America: Civil War we came to know that:
Winter Soldier killed Howard Stark and his wife to steal the super soldier serum and made it look like a car accident.
In the comics, per Wikipedia
In the comics, Howard and his wife Maria died in a car crash, as the result of faulty brakes arranged by either business competitors Republic Oil & Gas (later Roxxon Energy Corporation) or by the V-Battalion.
In Civil War we see that Bucky was under HYDRA's control, and he unwillingly crashed his car into the car with the Stark family. Then, Bucky got out and hit poor Howard on the side of his head multiple times, and strangled Mrs. Stark.
According to the comics, the canonical status of Howard Stark is that he is currently alive (or at the very least his fate is unknown). As for Maria, well that is a complete mystery.
In issue #1 of Jonathan Hickman’s run on “S.H.I.E.L.D.” While dicussing their families and duties Stark explains to Nathaniel Richards that due to the delicate natures of their mission the Brotherhood of the Shield arranged for the “deaths” of both agents. Stark continues to explain that his death was staged as an “automobile accident”. For whatever reason Maria’s involvement and ultimate fate is never mentioned.
The official timeline of the Marvel Cinematic Universe, published in the book Marvel Studios’ The Marvel Cinematic Universe: An Official Timeline, reveals that Howard Stark met his tragic end on December 16, 1991. He and his wife Maria were killed by the Winter Soldier (Bucky Barnes), who was acting under Hydra’s control. The murder was made to look like a car accident to hide the truth.
December 16, 1991 | The Stark Murders
Just before Christmas, Howard and Maria Stark are assassinated by the Winter Soldier (their deaths are disguised as a car accident). The Winter Soldier also acquires five samples of Super Soldier Serum from the vehicle. Hydra uses the packets to create more unstoppable assassins who, like the Winter Soldier himself, are kept in cryogenic storage when not on assignment. Decades from now, after the collapse of the parasitic Hydra operation that grew within S.H.I.E.L.D., the lab in Siberia where these super soldiers are stored will be abandoned and largely forgotten. But deadly potential lives on within.
Howard and Maria Stark are assassinated by the Winter Soldier after Howard spends a lifetime fighting against Hydra.

The Winter Soldier crashed their car into a fence,then punched Howard in the head twice,breaking his skull in half and his brain fall out,then the Winter Soldier went around and strangled his mom,crushing her throats and shooting the Security Camera.