SAN FRANCISCO -- Sparked by images and audio of children crying for their parents, hundreds of thousands of people worldwide are donating to non-profit organizations helping families separated at the U.S.-Mexico border.

Among those generating the most attention is a fundraiser started by a Silicon Valley couple. David and Charlotte Willner launched the fundraiser on Facebook over the weekend hoping to raise $1,500 -- enough for one detained immigrant parent to post bond. It had collected more than $13 million by Wednesday afternoon.

The money will go to a non-profit in Texas that offers free and low-cost legal services to immigrants.

More than 2,300 migrant children have been separated from their families at the border since May. President Donald Trump signed an executive order ending the process Wednesday.