Indiana Code Title 22. Labor and Safety § 22-3-3-2

Sec. 2. The notice provided for in the preceding section shall state the name and address of the employee, the time, place, nature and cause of the injury or death, and shall be signed by the injured employee or by some one in his behalf or by one (1) or more of the dependents, in case of death, or by some person in their behalf.  Said notice may be served personally upon the employer, or upon any foreman, superintendent or manager of the employer to whose orders the injured or deceased employee was required to conform or upon any agent of the employer upon whom a summons in a civil action may be served under the laws of the state, or may be sent to the employer by registered letter, addressed to his last known residence or place of business.