> through gross negligence

If you talk to someone with a law degree (judge, lawyer, whatever), they will tell you that "gross negligence" is very high barrier to cross in US law. Most people misunderstand that. It is very unlikely that any of the people in that chat group would be found grossly negligent, especially for their first mistake. Please do not read that last sentence as an apology or excuse for their behaviour; they should be reprimanded for it.