Donald Trump's troubled US election campaign has lost its second high-level member of staff of the day.
Michael Caputo, who was poised to serve as director of communications for the campaign at the Republican convention, resigned after firing off a celebratory tweet after news of campaign manager Corey Lewandowski's sacking broke.
He tweeted: "Ding dong the witch is dead!"
Accompanying the tweet was a photo from the Wizard of Oz, showing the feet of the Wicked Witch of the East protruding from under a house.
Trump campaign spokeswoman Hope Hicks confirmed Mr Caputo is no longer with the campaign.
Mr Caputo had served as the campaign's state director for the New York primary and as a senior adviser.
Mr Lewandowski was axed earlier in a shake-up designed to calm panicked Republican leaders.
He had been by Mr Trump's side since the beginning of his unlikely rise to become the presumptive Republican presidential nominee, but he clashed with those brought in to make the campaign more professional.
"I have no regrets," Mr Lewandowski told CNN, just hours after he was escorted out of Mr Trump's Manhattan campaign headquarters.
The former conservative activist seemed to acknowledge the limitations of his aggressive approach, which has sparked widespread concern among Trump supporters.
"The campaign needs to continue to grow to be successful," he said.
However Mr Lewandowski made clear that campaign chairman Paul Manafort, who has taken over from him, has been directing events.
"Paul Manafort has been in operational control of the campaign since April 7. That's a fact," he said
Ms Hicks described Mr Lewandowski's departure as a "parting of ways".
A source close to Mr Trump said Mr Lewandowski was forced out largely because of his poor relationship with the Republican National Committee and party officials.
The move came as Mr Trump faces continued deep resistance from many quarters of his party concerned by his contentious statements and his reluctance to engage in traditional fundraising.
Mr Trump was upset that so many Republicans such as House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell were reluctant to support him, and partially blamed Mr Lewandowski, according to the source.
"Firing your campaign manager in June is never a good thing," said veteran Republican operative Kevin Madden.
"The campaign will have to show dramatic changes immediately on everything from fundraising and organising to candidate performance and discipline in order to demonstrate there's been a course correction. Otherwise it's just cosmetics."
Mr Lewandowski has long been a controversial figure in Mr Trump's campaign, but benefited from his proximity to the presumptive Republican nominee.
He was a chief promoter of the idea that the best campaign strategy was to "Let Trump be Trump".
Mr Lewandowski frequently dismissed the notion that Mr Trump needed to hire more experienced political hands, spend on polling and sophisticated data operations, and moderate his rhetoric as he moved towards the general election.
Mr Lewandowski was charged with misdemeanour battery in the spring for an altercation involving a female reporter during a rally. The charges were later dropped. Mr Trump defended Mr Lewandowski throughout the episode and repeatedly framed his own actions as a sign of loyalty and a demonstration that he would not give in to outside pressure.
"Folks, look, I'm a loyal person," Mr Trump told voters at the time.
"It's so important," he said of loyalty in a subsequent interview. "And it's one of the traits that I most respect in people. You don't see it enough."
The move comes a day before Mr Trump is to attend a major New York City fundraiser, organised by long-time Republican financier Woody Johnson. Mr Trump will spend part of Tuesday and Wednesday at finance events in his home city.
Republican strategist Ryan Williams, a frequent Trump critic, said that Mr Lewandowski's dismissal "is the first major public admission from Donald Trump that his campaign is not going well".
"This shows donors, activists and party officials that he is willing to make significant changes, even if it means parting ways with a trusted political aide," Mr Williams said.
"Now Trump needs to demonstrate that he is willing to change his own approach by toning down his rhetoric and becoming a more disciplined general election candidate."