Workers’ compensation — Known loss — Action involving employer’s broker acquiring workers’ compensation insurance starting the day of job site injury where broker knew of the injury beforehand but did not inform insurer — Although policy technically took effect prior to the occurrence of the injury where coverage began at 12:01 a.m. on the date of loss because the policy did not set a specific time at which coverage was to begin, an insurer is not required to cover an insured’s known and undisclosed losses — Finding that insurer is not liable applies specifically to the known and undisclosed injury without more broadly affecting or canceling employer’s workers’ compensation coverage for other losses