I have a Google interview in 2 days but I’m not in a position to attend

I had scheduled the interviews 2.5 weeks after the initial discussion to give myself time to prepare. However, due to a sudden family emergency, I don’t think I’ll be able to attend the interviews scheduled for the day after tomorrow.

Would it be possible to postpone them? Given my situation, I’m concerned that if I reschedule again, the opportunity might not remain open. Is that something that typically happens?

I’m interviewing for an Applications Engineer role and have 3.4 years of experience.