An insured was sued in a personal injury action involving the use of a forklift on the insured's premises. The insured tendered its defense to the carrier of the company that employed the injured plaintiff. The employer's carrier refused to defend the insured. The insured's own commercial general liability carrier was then forced to defend the insured. Brian filed a declaratory action against the employer's carrier, arguing that the employer's carrier was obligated to defend the insured. The trial court agreed with that position and ruled that the employer's carrier had breached its duty to defend the insured in the underlying personal injury action. The trial court further ruled that, as a result of its breach of the duty to defend, the employer's carrier was estopped from asserting any coverage defenses to limit its obligation to indemnify the insured in the underlying personal injury action.