"deadly error" is a correct and usable phrase in written English.
You can use it to emphasize that a mistake or error is serious or has serious consequences. For example: "After making a deadly error, the stock market experienced a massive sell-off."
And there lies the deadly error.
"I thought that the U.S. had made a deadly error," he told The Guardian.
What recourse will there be for victims of a deadly error?
But it was blocking the aisle — a deadly error in his view.
After personnel at St . Agnes Medical Centerin Philadelphia committed a deadly error, the Centers for Disease Control and Prevention asked hospitals nationwide to change their laboratory procedures.
The report found "a series of tragic errors" including incorrect installations of gas pipelines, flawed testings and significant clinical and management failures caused the deadly error.
Legal rules impede police learning from deadly errors.
A series on the Martin Luther King, Jr. / Drew Medical Center — headlined "Deadly Errors and Politics Betray a Hospital's Promise" — singled out the hospital's leadership, which was African-American.
The United States military has repeatedly promised to work hard to avoid deadly errors, but American commanders consider night raids effective because they often catch militants off-guard.
And yet it is not hard to imagine less heartwarming consequences of this new revolution — biological weapons, for instance, or deadly viruses or mutant strains of common chemicals, not to mention the possibility of deadly errors.
"They can miss leads, they can trip over one another and it can lead to, when people are working undercover and they stumble across one another, deadly errors," Mr. Drewniak said.
