Parents say TikTok algorithms killed their kids

Chase Nasca, 16, took his life two years ago by stepping in front of a moving train. His parents and many others suspect TikTok drove him to suicide by bombarding him with more than 1,000 unsolicited, psychologically disturbing videos.

As Congress weighs legislation that could lead to a nationwide TikTok ban, opponents of the social media app say China’s access and control over the platform is just one of its problems. Critics say the app is uniquely harmful to children and deadly in some cases.

“It would be unwise to fail to acknowledge that what...