Illness?
Disability can often occur through illness, which usually involves a situation where there is no one "at fault" and therefore no one to sue for compensation.
Exceptions to this may be chemical exposures at work (in which case workers' compensation would be a possible source of compensation) other community exposures to toxic substances or contaminated food (in which case a law suit might be possible).
What other sources of compensation are there?
If you have a private insurance plan, personally or through work, disability coverage will likely provide income protection.
Employment Insurance provides a limited 15 week benefit during illness or disability
If your illness is likely to be prolonged and disabling, you may be eligible for Canada Pension Plan disability benefits