Ahh, anxious about taking this flight, land from my connecting, check in..

as I'm walking to security, the announcement came on. SQ21 has been cancelled.

Got a letter, checked into the Mariott.

FYI.. the letter says..

Dear Valued Customer,

Singapore Airlines apologizes for the unfortunate cancellation to your flight this evening.

Aircrafts Engine number 1 has an error and needs to be changed. The replacement engine is currently being sought. Once we have the replacement engine we will be changing the engine, which requires approximately 24 hours.

We are in the midst of arranging alternate flights for your travel. Unfortunately, there are no flights available for departure to Asia via Europe or any other way tonight.

While talking to other passengers, one of them had noted that there were a lot of empty seats.. Would SQ cancel a flight due to low numbers of PAX?