1.   It was not immediately known how serious the injuries were.

2.   It was not immediately known how serious the injuries were, said rail spokesman Bruno van Calster.

3.   It was not immediately known how serious the injury was.

4.   Van Heer later broke down in a relay event, although it was not known how serious her injury was.

5.   It was not immediately known how serious the shortages could become.

6.   It was not immediately known how serious their injuries were.