La. Legislature and Laws § 24:71
In the event of an attack, the governor shall call the legislature into session as soon as practicable, and in any case within ninety days following the inception of the attack. If the governor fails to issue such call, the legislature shall, on the ninetieth day from the date of inception of the attack, automatically convene at the place where the governor then has his office. Each legislator and each emergency interim successor, if the legislator for whom he was designated is unavailable, shall proceed to the place of session as expeditiously as practicable. When the legislature is convened as provided in this Section, the secretary of state shall deliver the panel designating emergency interim successors for each legislator who is unavailable due to attack to the house of representatives or the senate, as the case may be, and from said panel a final emergency interim successor to perform the duties of such unavailable legislator shall be chosen by lot from said panel under a procedure prescribed and conducted by the officers of the respective houses. The final emergency interim successor thus chosen shall then subscribe to the oath of office prescribed by the constitution and proceed to perform the duties of the legislator who is unavailable due to attack. At such session or at any session in operation at the inception of the attack, and at any subsequent sessions, limitations on the length of sessions and on the subjects which may be acted upon shall be suspended.
La. Legislature and Laws § 24:71