The phrase "a potential tragedy" is correct and usable in written English.
It can be used when discussing a situation that has the possibility of resulting in a tragic outcome.
Example: "The lack of safety measures in the construction site poses a potential tragedy waiting to happen."
Alternatives: "a possible disaster" or "a likely catastrophe."
"This is a potential tragedy for individual students".
Anyone who senses a potential tragedy in the making should pitch in to head it off.
That turns a matter of poor internal systems into a potential tragedy.
The plots of Shakespeare's last plays (Pericles, Cymbeline, The Winter's Tale, The Tempest) all contain a potential tragedy but one that is resolved by nontragic means.
This is a potential tragedy that may have become one of the most magnificent days in the history of New York City agencies".
It is an anguished contemplation of life, death and sex among three friends in their early 20's reacting instinctively to a potential tragedy.
The story quotes the United Nations Intergovernmental Panel on Climate Change estimates that millions of people in the area may be displaced by 2050 under such conditions, an immense potential tragedy and contribution to the further distress of a country of 152 million, already poor, mostly unemployed, and understandably uncertain and insecure.
When you consider the damage that deer can do to a car and the people in them (I was once told a story in North Bay about a guy who got decapitated when he hit a deer, after its antlers came through his windshield), 1.6 collisions per day in a town of 110,000 is a lot of potential tragedy, auto-insurance, or venison depending on how you look at it.
The county fair -- so American, so farmlike -- is in itself a seething mass of potential tragedy.
Out of social chaos and potential tragedy, a resurrection of human order and decency gilded the spring.
But for 25 million Americans, including 7 million children, with asthma, that cough alerts the asthma sufferer or parent to pull out an inhaler to avert potential tragedy.
