The Assassination of Wolfgang von Strucker was one of the opening actions in the Ultron Offensive.
The location of Wolfgang von Strucker's Sokovian base was discovered by Phil Coulson and transmitted to Maria Hill. The Avengers officially reassembled and spearheaded an assault on the fortress. Their objectives was to dismantle the leadership and operational capabilities of one of HYDRA's last remaining strongholds, and to reclaim the Scepter. The HYDRA operatives were all killed or captured, and the base was taken in short order. However, Wanda Maximoff and Pietro Maximoff engaged the Avengers in an attempt to stop them. Though they were ultimately unsuccessful, the visions imparted to Tony Stark by Wanda were powerful enough to spur him into completing the Ultron Program as soon as possible.
In the aftermath, von Strucker of HYDRA was taken into custody by NATO, who placed him in a European jail.
When the Avengers returned to their headquarters, Stark was able to convince Bruce Banner to use the power of the Scepter to finish the construction of Ultron, a peacekeeping program. Unfortunately, the artificial Intelligence became unexpectedly sentient, and attacked J.A.R.V.I.S. and the Avengers by possessing various Iron Legion drones at an after-party.
After the brief skirmish and the destruction of his first crude body, Ultron transmitted his consciousness to now-abandoned HYDRA Research Base, and recruits the Maximoff twins by manipulating their hatred of the Avengers and the unrest in their country.
Ultron tracked Wolfgang von Strucker to his cell and demanded to know the location of Vibranium caches, for use in his plans to both build a new body and create an extinction-inducing meteor. Strucker gave Ultron the information he needed: The name and location of Strucker's Vibranium dealer Ulysses Klaue. Ultron promptly killed Strucker by smashing his head hard against the wall of the cell. In a grisly and foreboding message to the Avengers, Ultron painted Strucker's cell wall with the word "peace", written in Strucker's own blood.
Werner von Strucker inherited his father's wealth. Grant Ward, the self-appointed leader of HYDRA, convinced Werner to join his campaign, citing the fact that his father had died a death meaningless to HYDRA.