Legal Question in Employment Law in California

The short answer is, it depends.

Non-exempt (hourly) employees are entitled to compensation for all hours worked. Thus, if a non-exempt employee were sent home in the middle of the day due to an emergency beyond the employer's control, he/she would only be entitled to compensation for the hours he/she actually worked. An exempt (salaried) employee, on the other hand, is entitled to be compensated in full for any workweek in which he/she performs any work. Thus, as long as he/she performed some work during the week in which the emergency occurred, he/she would be entitled to a full week's compensation for that workweek.

Of course, the above is only a general iteration of the law and should not be relied upon as legal advice in your specific situation. Speak to an employment lawyer if you would like legal advice.

Good luck to you.