Short answer: Yes. A fiduciary who breaches ERISA duties is personally liable to make good the plan’s losses from the breach and to give back any profits made from plan assets, and a court can order other relief, including removal.
ERISA section 409 makes a breaching fiduciary personally liable to restore losses to the plan caused by the breach and to restore profits the fiduciary made through use of plan assets. A court may also order other equitable relief and remove the fiduciary. A person is not liable for a breach committed before becoming, or after ceasing to be, a fiduciary.
Because liability follows whoever acts as a fiduciary, business owners, officers and benefits committee members on a self-funded plan should know which of their decisions make them fiduciaries. Fiduciary liability insurance is worth discussing with the employer; it is a different product from an ERISA fidelity bond, and what it covers depends on the policy.