I used a truck to travel for the company I worked for, I was totaled in an accident. Can I claim any part of the loss?

That depends.

If you personally owned the vehicle, and claimed a deduction for mileage or actual expenses, then no.  Your business use was covered by those deductions. (And, if you are a W-2 employee, you haven't even been allowed to take those mileage deductions since 2018.)

If you were self-employed and deducted the mileage or actual expenses as a business expense on schedule C, you can't take an additional deduction for the loss, and you might even have a taxable event if you were reimbursed by insurance, depending on how much depreciation you claimed over the years.

If a business owns the vehicle, and the vehicle is listed as a business asset, the business can claim a loss.  You would list the asset as "sold" either to the insurance company for the amount of the settlement, or to a salvage yard for the salvage value.  Depending on the original cost, how much deprecation you claimed over the years, and the salvage price or reimbursement value, you might have taxable business income or a deductible  business loss.