The American-English phrase bad day at Black Rock denotes a fateful day that brings disaster.

It alludes to Bad Day at Black Rock, the title of a 1955 U.S. thriller film, directed by John Sturges (1910-92), starring Spencer Tracy (1900-67) and Robert Ryan (1909-73). The following is from the review of this film, by Dorothy R. Powers, published in The Spokesman-Review (Spokane, Washington) of Saturday 12^th March 1955:

“Bad Day” is the story of a brutal, fear-smogged town in Arizona. When the streamliner stops at Black Rock for the first time in four years, a stranger (Tracy) alights. Nobody knows why he came, and he tells no one. He just starts asking questions about the strange disappearance of a Japanese farmer.
When he discovers the farmer had been murdered by a local hoodlum (Robert Ryan), Tracy’s own life becomes worthless. He’s told by virtually every soul in town he’ll be dead by nightfall and told, as well, that they won’t hep [misprint for ‘help’] him.

The earliest figurative uses of bad day at Black Rock that I have found:
1: either refer to actual places named Black Rock;
2: or appear in relation to sports.

1: REFERENCES TO ACTUAL PLACES NAMED BLACK ROCK

The following use of bad day at Black Rock refers to Black Rock, in Polk County, Oregon—Charles Ireland, Valley Editor, wrote the following in Survey Shows Kill Below Previous Year, published in The Oregon Statesman (Salem, Oregon) of Sunday 30^th September 1956:

Deer season opened without much of a bang Saturday in the mid-valley.
It was truly a bad day at Black Rock for hundreds of hunters. And it wasn’t any better in the Abiqua Basin or the North Santiam Canyon.
Buck deer, comparatively hard to bag a year ago on opening day, were even scarcer yesterday.
A Statesman check with 25 mid-valley food lockers tallied only 68 deer that had been brought in for butchering. A year ago, the comparable figure was 100.
Far Cry From 1954
And it was a far cry from 1954, when 152 deer were taken on opening day alone from Polk County’s forested Black Rock area, west of Falls City.

Two other early figurative uses of bad day at Black Rock refer to actual localities named Black Rock. The first is from The Pittsburgh Press (Pittsburgh, Pennsylvania) of Monday 28^th January 1957:

Bad Day at Black Rock Sees Six Perish in Fire
Moncton, N. B., Jan. 28 (UP)—Fire raced through a home at nearby Black Rock, claiming the lives of six members of one family and injuring five others.
Dead were Mrs. Moise Savoie, 55, her son and daughter-in-law, Mr. and Mrs. Wilfred Savoie, and their one-month-old son and a niece, and the elder Savoies’ adopted six-year-old daughter.

The second is from the Springfield Leader and Press (Springfield, Missouri) of Saturday 15^th June 1957:

Bad Day at Black Rock For Frisco Engineer
Walnut Ridge, Ark.—A Frisco freight train was reported to have derailed 3 miles west of Black Rock early today.
First reports said six cars and the caboose left the track, and that there was some damage to the track.
Black Rock is 12 miles west of Hoxie.

2: USES OF BAD DAY AT BLACK ROCK IN RELATION TO SPORTS

The earliest allusive use of bad day at Black Rock that I have found is from U. L. Faces X— Foe That Beat ’Em 40 Points, by Johnny Carrico, published in The Courier-Journal (Louisville, Kentucky) of Wednesday 29^th February 1956—this article was about two basketball teams, the Louisville Cardinals, representing the University of Louisville, Kentucky, and the Xavier Musketeers, representing Xavier University in Cincinnati, Ohio:

“Bad Day at Black Rock.” That is the oblique reference Louisville players use in recalling that 40-point shocker when Xavier barbecued the Cardinals roughly two weeks ago in Cincinnati.

The earliest instance that I have found of bad day at Black Rock as a proper phrase is from The Greenville News (Greenville, South Carolina) of Saturday 19^th October 1957:

Citadel Looks For Big Win Over Spiders

Charleston, Oct. 18 (AP)—A bad day at Black Rock behind them; a golden opportunity ahead.
That’s the way coach Eddie Teague and his Citadel Bulldogs view tomorrow night’s Southen [sic] Conference football clash with the University of Richmond at Johnson Hagood Stadium. The kick-off is set for 8 p.m. and a crowd of between 10,000 and 15,000 persons is expected.
The Bulldogs had their bad day last Friday when they were soundly trounced by Wofford 34-0. Their golden opportunity lies in the fact that they currently shared [sic] the top spot in the Southern Conference standings with Virginia Military, 2-0, and could enhance that position with a victory over the Spiders tomorrow night.

The second-earliest occurrence that I have found is from the Denton Record-Chronicle (Denton, Texas) of Sunday 7^th September 1958: the results of the weekend’s baseball games in both the American League and the National League appeared—for no apparent reason—under the title of Bad Day at Black Rock.

A few days later, in The Odessa American (Odessa, Texas) of Thursday 25^th September 1958, Spec Gammon began his column Along Athletic Avenue with:

It was a bad day at Black Rock last week for football prognosticators, especially those who ply their trade in Texas schoolboy circles.