Answer:
Dear Diary, I remember the day I prevented something catastrophic from happening. Now I think about it, it's funny but it wasn't then.
It happened that I prevented a possible gas explosion last year. I went to visit my friend down at her house and somehow after using the gas to cook, Mary, my friend forgot to turn it off and the kitchen was reeking of cooking gas.
What was scarier was that her father was at the den smoking with his friends that also came over and you know how smoke or fire can trigger a gas explosion. I went to the kitchen to get something and luckily smelt the gas in the air, immediately switched it off, dialed 911,s and raised an alarm.
I quite possibly prevented a gas explosion that would have been really tragic and catastrophic.