ドアはひとりでに開いた

the door opened by itself

→ ドア
phrase Rare #38,369
the door opened by itself Describes the door opening on its own, without anyone apparently causing it. ひとりでに means “by itself” or “of its own accord.”
JA: 不思議なことに、ドアはひとりでに開いた。
EN: Strangely, the door opened by itself.

奇妙なことにドアはひとりでに開いた

Strangely, the door opened by itself.

そのドアはひとりでに開いた

The door opened by itself.

不思議なことにドアはひとりでに開いた

Strangely, the door opened by itself.

もないのにドアはひとりでに開いた

The door opened by itself even though there was no wind.