Wikipedia is fighting to preserve the memories of the 20 million artifacts lost in Sunday's Brazilian museum fire.
The Museu Nacional in Rio -- one of the largest museums in the Americas -- and irreplaceable objects like the oldest human fossil found in Brazil and a 5.5-ton meteorite found in 1784 are believed to have been lost.
"There were over 20 million objects inside the #MuseuNacional. Did you take a photo of any of them? Help us preserve the memories of as many as we can and add them to @wikicommons," Wikipedia tweeted Tuesday, with an explanation on how to do so.
The cause of the fire remains unclear, but the incident fueled criticism of Brazil's dilapidated infrastructure and budget deficits as October's national elections approach, CBS News reports.
The museum's director noted that a portion of the collection was destroyed but that the museum hasn't yet determined how much. Authorities say the gutted structure is unsafe to enter because the roof and internal walls are compromised and may collapse.
"The fire at the National Museum of Brazil has led to the devastating loss of 200 years of memory," Katherine Maher, executive director of the Wikimedia Foundation, said in a statement.
"At Wikipedia, our community is hard at work every day curating a living record of our shared heritage," Maher said. "With this effort, we're asking people everywhere to join our global community and help the world recover from this collective tragedy."
First published Sept. 5, 5:19 a.m. PT
Update, 10:14 a.m.: Adds statement from Wikimedia.