Erin Berkowitz lost her rental home in Altadena to the Eaton fire. The blaze destroyed her home art studio, the outdoor kitchen where she created textile dyes and her business inventory, including hundreds of pieces of custom-made clothing and accessories.

To help with her losses, a friend created a fund-raising page for her on GoFundMe. But within hours, she learned that there was another GoFundMe page that looked identical to the one her friend created, except for a slightly different URL.

“Someone has tried to just make their way in and try to profit off of my tragedy,” said Ms. Berkowitz, a 36-year-old artist and educator.

The page appeared to be one of several fake online fund-raisers that Los Angeles officials have warned people to watch out for. Such sites detailing stories of loss and desperation — family homes obliterated, neighborhood schools in ruins, restaurants desperate to rebuild — are now a ubiquitous symbol of the destruction wrought by the fires. But scammers can use them to prey on the generosity of people across the globe.

“We’re concerned, as has been mentioned in previous press conferences, that there’s a number of sites that are fake,” Mayor Karen Bass said Thursday morning.

Rob Bonta, California’s attorney general, said at a news conference last weekend that scammers can create “fake organizations masquerading as charities,” often targeting elderly people and those whose first language is not English.

“We have people with big hearts who want to help,” he said. “We also see scammers who are taking advantage of that goodness and that generosity.”

GoFundMe said that more than $100 million has been raised on its platform to help victims of the Los Angeles fires.

Ms. Berkowitz was particularly worried that the mere existence of a fake page — which GoFundMe has since taken down — would jeopardize the thousands of dollars that the page her friend made had raised.

“This is now my lifeline to survival. Someone has threatened it,” she said of her thinking when she learned about the fake page.

Ms. Berkowitz said there was also an Instagram account with a username that was almost identical to hers that was asking her friends and family to donate to the fake GoFundMe page. Ms. Berkowitz said Instagram had initially refused to take the account down, but a Meta spokesman said on Thursday that it had been removed for violating policies.

Consumer protection experts urged people to be vigilant with donation sites and try to verify the account organizing the fund-raiser before sending any money.

Among the red flags to look out for, according to Ally Armeson, executive director of the nonprofit FightCybercrime.org: unsolicited contact for donations; requests for upfront payments in exchange for disaster aid; requests for personal information like a Social Security or bank account number; and aggressive responses to attempts to verify the page.

Ruth Sesswein, the director of consumer protection at the nonprofit Consumer Action, recommended looking up donation organizers on social media and confirming their connection to the beneficiary of the fund-raiser.

To prevent people from falling for scam sites, GoFundMe has set up a page to spotlight verified fund-raisers to help victims of the fires. A team of experts approved all of the fund-raisers on the page.

A spokeswoman said there are also protections in place to detect fake pages, such as “machine learning to catch higher-risk donations, image and video review to prevent abusive behavior, and partnerships with law enforcement to verify outstanding cases.”