TRENTON, N.J. (AP) — Lt. Gov. Sheila Oliver, who rose to become one of New Jersey’s most prominent Black leaders and passionately advocated for revitalizing cities and against gun violence, died Tuesday after a sudden illness. She was 71.

No cause of death was given, according to a statement from her family issued by Gov. Phil Murphy ’s office. Oliver was serving as acting governor while Murphy and his family are on vacation in Italy. His office said she had been hospitalized on Monday.

Murphy said he and his family are distraught at the news. Naming Oliver as his lieutenant governor was, he said, “the best decision I ever made.”

She was the first Black woman to hold statewide elected office in New Jersey, winning the vote alongside Murphy in 2017 and again in 2021. She was a well-known figure in state government, and made history in 2010 by becoming the first Black woman to lead the state Assembly.

In contrast to her predecessor, who rarely appeared alongside Gov. Chris Christie, Oliver regularly stood at Murphy's side and signed several bills into law while serving as acting governor.

She was a compelling public speaker and frequent attendee at Murphy’s bill signings and other events, where he typically introduced her as his “rocking” lieutenant governor.

In 2021 while unveiling tighter gun legislation alongside Murphy, Oliver’s voice cracked as she lamented the gun violence that disproportionately affected cities in the state and lamented what she suggested was runaway gun violence.

“We are tired of funerals and memorials,” Oliver said. “Growing up in Newark, I tell young people I could go to any section of this city by myself or with my friends. Our young people cannot do that today.”

In 2021, she signed a bill that established a pilot program to overhaul the state’s juvenile justice system in four cities and which aimed to reintegrate young people into their communities. Another measure she signed in 2021 revived a defunct fund for “urban enterprise zones” aimed driving economic development in cities through lower sales tax rates.

In addition to serving as Murphy’s top deputy, stepping in while he was out of the state, she also oversaw the Department of Community Affairs, which coordinates state aid to towns and cities and supervises code enforcement.

Her sudden illness and death seemed to have stunned officials.

“This is devastating news. I am shocked at the passing of Lieutenant Governor Oliver. Sheila is a pathbreaker and has been one of the foremost leaders of our great state for decades. I am still processing this,” Rep. Bill Pascrell Jr. said in a statement.

Christie, who’s running for the Republican nomination for president, worked with her during his first term when she was Assembly speaker and remembered her as “a great person and partner” and said in a tweet that her passing was a loss for him personally as well as the state.

Murphy’s office announced on July 31 that Oliver was admitted to Cooperman Barnabas Medical Center in Livingston with an undisclosed medical condition. The governor’s office declined to elaborate.

Her family’s statement remembered her as “our cherished daughter, sister, aunt, friend, and hero.”

Murphy spokesperson Mahen Gunaratna said the governor will be “returning soon” but didn’t specify when. He was set to return Aug. 13.

Oliver served in the Assembly since 2004 and was on the Essex County board of chosen freeholders from 1996 to 1999. Born and raised in Newark, she earned a sociology degree from Pennsylvania’s Lincoln University.

“She brought a unique and invaluable perspective to our public policy discourse and served as an inspiration to millions of women and girls everywhere, especially young women of color,” Murphy said in a statement Tuesday. "Beyond all of that, she was an incredibly genuine and kind person whose friendship and partnership will be irreplaceable.”

Oliver was just the second person to hold the post of lieutenant governor, a newer state government position that began under previous Gov. Chris Christie.

It was unclear who would immediately succeed her. New Jersey's constitution calls for Senate President Nicholas Scutari to serve as acting governor if the governor and lieutenant governor are out of state or incapacitated. The constitution requires Murphy to appoint Oliver’s successor within 45 days.