"I have decided that in the interest of making sure that we can start the Democratic convention on a high note that I am not going to gavel in the convention," Wasserman Schultz told the Sun Sentinel newspaper in an interview.
Baltimore Mayor Stephanie Rawlings-Blake, who is also the Democratic National Committee's secretary, handled the gaveling instead.
"Delegates, alternatives, standing committee members and all of our honored Democrats and other guests here in Philadelphia and all of you who have joined us by television, radio and online, here in the United States and around the world," she said, "I hereby call the 47th quadrennial Democratic National Convention to order."
Wasserman Schultz will also not speak tonight or throughout the duration of the convention, a Democrat close to her says. She will remain in Philadelphia until Friday when she formally steps down as leader of the committee.
Wasserman Schultz changed her plans as the fallout deepened from leaked DNC emails that appeared to show the committee favoring presumptive Democratic nominee Hillary Clinton over Sanders during the primary. It became clear Monday that the convention floor could erupt in anger if she gaveled the convention into session or sought to speak.
And the Democratic National Committee issued an apology to Sanders moments after the convention opened, likely hoping to help soothe tensions heading into the week.
"On behalf of everyone at the DNC, we want to offer a deep and sincere apology to Sen. Sanders, his supporters, and the entire Democratic Party for the inexcusable remarks made over email," the statement said. "These comments do not reflect the values of the DNC or our steadfast commitment to neutrality during the nominating process. The DNC does not -- and will not -- tolerate disrespectful language exhibited toward our candidates. Individual staffers have also rightfully apologized for their comments, and the DNC is taking appropriate action to ensure it never happens again."
The morning Florida delegate meeting descended into chaos when Wasserman Schultz took the stage, with critics holding up signs with the word "emails," and Sanders supporters booing the congresswoman loudly, even after she began speaking.
"We have to make sure that we move forward together in a unified way," Wasserman Schultz said during brief remarks. "We know that the voices in this room that are standing up and being disruptive, we know that is not the Florida that we know. The Florida that we know is going to make sure that we continue to make jobs."
The audience was roughly half supportive of Wasserman Schultz and half detractors, though the angry participants were louder than the other half. Those attendees began to chant, "Shame! Shame! Shame!" while Wasserman Schultz was speaking.
Sanders tried to quell some of his dissatisfied supporters at a rally before his expected speech Monday.
"We have got to elect Hillary Clinton and Tim Kaine," Sanders said, which prompted some attendees to shout him down.
Wasserman Schultz announced Sunday she is stepping down as chairwoman of the DNC at the end of the party's convention. The drama reinforced concerns about Democratic party unity.
Former Sanders campaign manager Jeff Weaver tried to show a unified Democratic Party on Monday, the morning after Wasserman Schultz announced her resignation.
"This happened, we knew it happened then, now is the time to go forward,' Weaver told CNN's Chris Cuomo on "New Day" on Monday. "Now is the time to elect Hillary Clinton and defeat Donald Trump."
Wasserman Schultz talked with both President Barack Obama and Clinton before making announcing her upcoming resignation, a Democratic source said.
"Going forward, the best way for me to accomplish those goals [which include electing Clinton president] is to step down as Party Chair at the end of this convention," Wasserman Schultz said in the statement.
"As party chair, this week I will open and close the Convention and I will address our delegates about the stakes involved in this election not only for Democrats, but for all Americans," she said.
DNC Vice Chairwoman Donna Brazile will serve as interim chair through the election. She had been a CNN political commentator, but CNN and Brazile have mutually agreed to suspend their contract, effective immediately, although she will remain on air during the convention week in an unpaid capacity, CNN said. CNN will revisit the contract once Brazile concludes her role.
Separately, a Democratic operative said Hispanic leaders close to Clinton and her high command were discussing Housing Secretary Julian Castro as a possible successor to Wasserman Schultz at the DNC helm, among a number of other candidates whose name are being mentioned.
Chants of "Debbie is done!" and "Debbie resigned!" broke out at a pro-Sanders rally Sunday in Philadelphia after the news was announced.
Party officials decided Saturday that Wasserman Schultz would not have a major speaking role or preside over daily convention proceedings this week. The DNC Rules Committee has named Rep. Marcia Fudge, D-Ohio, as permanent chair of the convention, according to a DNC source. She will gavel each session to order and will gavel each session closed.
"She's been quarantined," another top Democrat said of Wasserman Schultz, following a meeting Saturday night but before her announcement that she was leaving.
Both sides of the aisle react
Obama issued a statement, saying, "For the last eight years, Chairwoman Debbie Wasserman Schultz has had my back. This afternoon, I called her to let her know that I am grateful."
And Clinton thanked Wasserman Schultz for her leadership of the party.
"I am grateful to Debbie for getting the Democratic Party to this year's historic convention in Philadelphia, and I know that this week's events will be a success thanks to her hard work and leadership," Clinton said.
After slamming Wasserman Schultz as "highly overrated," Trump, speaking at a rally in Roanoke, Virginia, knocked Clinton for being disloyal to the soon-to-be former DNC chair.
"How about that for disloyalty in terms of Hillary Clinton. Because Debbie Wasserman Schultz has been so much for Hillary Clinton," Trump said. "These politicians. There's no loyalty there. No loyalty. None whatsoever."
"It gets a little heat and they fire her," Trump said. "Debbie was totally loyal to Hillary and Hillary threw her under a bus and it didn't take more than five minutes to make that decision."
Wasserman's Republican counterpart, Reince Priebus, said, "I think the day's events show really the uphill climb Democrats face this week."
"The extreme left will not be satisfied by one person's resignation," the Republican party national chairman added.
Trump campaign chairman Paul Manafort said Clinton should follow Wasserman Schultz out the door.
"Debbie Wasserman Schultz resigned over her failure to secure the DNC's email servers and the rigged system she set up with the Clinton campaign," he said in a statement. "Now Hillary Clinton should follow Wasserman Schultz's lead and drop out over her failure to safeguard top secret, classified information both on her unauthorized home server and while traveling abroad."
Weaver called Wasserman Schultz's departure a win on CNN's "Erin Burnett OutFront" on Sunday.
"I think what the signal was today is that the voices of Bernie Sanders supporters have been heard," he said. "And other people, frankly, in the party, Hillary Clinton supporters, who felt this was the last straw, that she had to go, and this shows they have been heard and gives us opportunity to move forward toward November -- united to deal with the problem of Donald Trump."
Wasserman Schultz's stewardship of the DNC has been under fire through most of the presidential primary process, but her removal from the convention stage comes following the release of nearly 20,000 emails.
One email appears to show DNC staffers asking how they can reference Sanders' faith to weaken him in the eyes of Southern voters. Another seems to depict an attorney advising the committee on how to defend Clinton against an accusation by the Sanders campaign of not living up to a joint fundraising agreement.
Before the announcement, Sanders on Sunday told Tapper the release of the DNC emails that show its staffers working against him underscores the position he's held for months: Wasserman Schultz needs to go.
"I don't think she is qualified to be the chair of the DNC, not only for these awful emails, which revealed the prejudice of the DNC, but also because we need a party that reaches out to working people and young people, and I don't think her leadership style is doing that," Sanders told Tapper on "State of the Union," on the eve of the Democratic National Convention in Philadelphia.
"I am not an atheist," he said. "But aside from all of that, it is an outrage and sad that you would have people in important positions in the DNC trying to undermine my campaign. It goes without saying: The function of the DNC is to represent all of the candidates -- to be fair and even-minded."
He added: "But again, we discussed this many, many months ago, on this show, so what is revealed now is not a shock to me."