Has “passed away” always been a straight euphemism for “died”?

I’ve told this story before, but I used to work with an online cancer support group. There was a young woman on the group whose young husband was dying of cancer. I suspect woman had heard the expression “ passed away” but had never seen it written.

Her last post to the group was titled My Husband Past Away. I always thought there was something touching and oddly appropriate in this construct, even though it was accidental.

Here is an example of the term “passed away” where a man was killed in an industrial accident while dismantling gas rigs. Definitely not limited to a quiet death in a peaceable setting.

Were they on a two-lane road when the driver tried to get by slow traffic on a hill?

In speech, which ngram doesn’t index, even today pass away is by far most collocated with death by natural causes, such as “cancer,” specific forms of cancer, or “heart attack.”

If we exclude printed instances in obituaries, (which mechanically employ this expression in a formalized way), it tends to be used more in speech. Over all, though, it seems from a quick survey that pass away is most frequently used without mentioning the cause of death (passed away in his sleep, passed away at the age of XX, etc.) and I see no indication that this has changed since the 1990s.

In 1993, Howard Dean said on the PBS Newshour: “Carroll Campbell and I sat with the President and Ira Magaziner and the First Lady for almost a year now with Roy Roemer and George Wilson before he passed away in that plane crash.”

In 2003, a CNN anchor said, " A reminder that John Holliman, unfortunately, passed away in a tragic car accident a few years ago, otherwise, he’d be with us, as well."

From looking over the data quickly (in COCA), it seems that collocations with a violent form of death tend to be when describing deaths having occurred further in the past. I would be curious to see which data or specific examples the OP is referring to that indicate any real change in the usage of pass away.

Right. This is known as the “euphemism treadmill.” The crippled-handicapped-disabled-whatever it is now sequence being the canonic example.

Yes, Google Ngram is a nice resource, but if you really want to study usage, you need to use a real corpus, where each word is coded. Ngram only looks at books, so it doesn’t track spoken language, which is its major inadequacy. It also doesn’t allow you to search for collocations by word form, or do a cumulative search for lexemes. For example, if you’re looking for instances of a term like drive (someone) crazy, you have to search for drive crazy, driving crazy, drove crazy, and has/had/have driven crazy all separately.

Also, with a corpus, you can sort out the newspapers from the magazines and speech, to see how many instances are in something like an obituary, where you kind of have to use the phrase pass away, as it’s part of the discursive formula for that kind of publication.

On the other hand, the great value of Google Ngram is that it goes way back in history. Most corpora go back only to the 1990s. It all really depends upon the nature of the question you are researching.

Here is a search for noun forms that collocate 1-3 positions after passed away, broken down by spoken language, newspapers, magazines, academic and fiction, disaggregated by the last three decades. “Accident” is #16 in frequency. I don’t see any other words which would indicate violent forms of death.

The first word following was set to a preposition wildcard, so it included phrases like:*passed away from . . .
passed away in . . .
passed away during . . .
*etc.

This is a corpus of 560 million words from 1990 to 2017, equally divided among spoken, fiction, popular magazines, newspapers, and academic texts.