I read this story many years ago as a teenager.
It is set in an overpopulated near future. A man and his pregnant wife are at home in their small apartment.
Suddenly an public announcement is made on the TV, that an asteroid (?) is going to hit the Earth. The government has prepared deep underground shelters for just such an emergency, but there are only limited places in the shelters. To be fair, tickets will be made available and everyone will have the chance to get one (can't remember how). Anyway, the protagonist goes out in search of tickets. So does everyone else, and mass panic, rioting and bloodshed follow. Somehow, after much tribulation, he manages to get a ticket. He returns to the apartment exhausted and traumatised, but at least he knows that his family will be guaranteed safety.
Then there is another announcement on the TV, saying the whole thing was a government hoax, to reduce the population. This tips the man over the edge, and he shoots his wife.
The story sounds morbid and implausible, but I'm just curious as to who wrote it.