It depends on what kind of protection you've got. A company cannot thrive without its workers, although there are external steps that can be taken outside the reach of health and safety.
About half of the firms would collapse if a key figure in the company died or became seriously ill. There is no warning sign that you should put up for that, but a company could set up a form of business security called keyman insurance. This could cover any future missed income, debt repayments or costs of replacing a member of staff or director who is vital to their service.
If you are unaware which business protection plan you may contact a nearby business protection advisor in London and they can advise you which is the most suitable protection policy for your business.