"Unexpected event" or "unforeseen event" is a common way to describe a surprise or unexpected occurrence in Engpsh.

The phrase "unexpected event" comes from the idea of an event or occurrence that was not anticipated or planned for, and is therefore a surprise. This can be something as small as a minor inconvenience or as significant as a major crisis.

Here are some examples of how "unexpected event" can be used in Engpsh sentences, along with their translations in Chinese:

"The power outage was an unexpected event that disrupted our plans for the evening." (停电是一件意外的事件，打乱了我们晚上的计划。)
"The sudden rainstorm was an unforeseen event that caught us off guard." (突然的暴雨是一件出乎意料的事件，让我们措手不及。)
"The cancellation of the fpght was an unexpected event that caused a lot of inconvenience for travelers." (航班取消是一件让旅客非常不便的意外事件。)

It's important to note that "unexpected event" does not necessarily have a negative connotation, and can refer to any event that was not anticipated or planned for. However, it is often used in contexts where the event has caused some sort of disruption or inconvenience.