The most senior and second-longest-serving senator, Inouye died died of respiratory complications on Monday evening, according to the Associated Press.
His death leaves a vacancy that Hawaii election law dictates will be filled by an interim appointment from the governor. Abercrombie will have to choose from a list of three potential appointees submitted by the Hawaii Democratic Party.
Whoever he appoints will serve until a special election in 2014, where Hawaii voters will choose a senator to serve the remainder of Inouye's term, until 2016.
Inouye had planned to run for a record 10th term in 2016.