Legal Question in Personal Injury in California

Depends on the terms of your written rental/lease agreement. Read it to see what it says.

Yes, if the fire dept or building inspector red tagged the place as uninhabitable, then you will legally be forced to move out immediately.

If there is no written agreement or if this isn't covered in your written agreement, then the issue becomes" if the "accident" was entirely not your fault, nothing to do with you, then the landlord would be obligated to repair, and might be obligated to put you up in a motel for a couple days while the property is being repaired. If the property was substantially damaged, with repairs to take a long time, then the landlord and tenant would be relieved of their obligations under the agreement. You would not have to be provided any alternative living quarters or money. A good landlord might help you out since it wasn't your fault. You would be entitled to return of any deposits not otherwise claimed, and any unused rent paid in advance for the days you are not able to stay there.

If the damage was your fault, plan on being sued, and your deposits forfeited.

A lease is, in many ways, the same as if you owned the place for a period of time. One of the risks of that is if it is not covered by other provisions in the lease, a fire or other damage to the property may put you on the street with no recourse to anyone else, just as if you owned the place. Your landlord cannot charge you rent while the premises are not habitable, but they don't owe you anything extra unless the lease or a rent control ordinance says they do. Of course if the damage is due to some fault of the landlord, then that is a whole other story.