The phrase "almost completely destroyed by" is correct and usable in written English.
It can be used to describe something that has been severely damaged or ruined, typically by an external force or event.
Example: "The ancient ruins were almost completely destroyed by the earthquake that struck the region."
Alternatives: "nearly obliterated by" or "virtually annihilated by".
The town was almost completely destroyed by fire in 1796.
They were almost completely destroyed by the earthquake of 1923 and the aerial bombings of 1945.
This collection, twice as big as the first, was almost completely destroyed by the Germans in 1940.
Her comments followed a daylong tour of two small towns along the southern coast that were almost completely destroyed by the earthquake and the tsunami that followed.
After being almost completely destroyed by fire in 1865, Karlstad was rebuilt along modern lines, with broad avenues and large parks.
The 16th-century town was almost completely destroyed by Allied bombing in September 1944 and had to be quickly and cheaply rebuilt.
Beichuan was one of the areas nearly completely destroyed by the earthquake of 12th May , 2008
Vortex shedding was almost completely destroyed, resulting in a reduction by 85% in the vortex strength, by 71% in the structural vibration amplitude, and by 30% in the drag coefficient.
The following year, the synagogue's two-story frame synagogue building at 326 Keap Street, valued at $2,000 (today $), was struck by lighting and almost completely destroyed.
Here, two companies of horse artillery, under an officer called Marin, a veteran of the campaigns in Italy and Egypt and personal favourite of the Emperor, were almost completely destroyed, with their guns and commander captured by the enemy.
By 1 December, the division was almost completely destroyed; it lost virtually all of its heavy equipment and vehicles, as well as suffering 4,940 men killed or missing.
