Elon Musk has been goaded into using his vast amount of wealth to fix Flint's water problems.
The SpaceX and Tesla boss has been criticised in recent days for the nature of his attempts to help with the rescue of the Thai boys from a cave, during which he built a submarine that was rejected by the leaders of the rescue operation. Many people that argued that the billionaire could use his huge wealth more effectively, by paying for civil or charitable projects.
And one of those people has now successfully called out Mr Musk and made him commit to helping out with problems at home.
Flint's water crisis came to public attention in 2014, when it was reported that the city's piping was leaking dangerous levels of lead into people's water supply. The state's Department of Environmental Quality has said that the water is clean enough to drink – but the problem will not be fixed until the city's pipes are replaced, and residents have been advised to keep using filters or drink bottled water.
Since then, many critics of Mr Musk have taken to reminding him of the problem and the possibility he could fix it on Twitter. One of those reminders appears to have finally worked, after a post that goaded Mr Musk into helping.
"Hey Elon Musk I heard a bunch of people saying there's NO WAY you could help get clean water to Flint, Michigan," wrote one Twitter user. "Said you wouldn't be capable idk."
Mr Musk almost immediately replied to the taunt.
"Please consider this a commitment that I will fund fixing the water in any house in Flint that has water contamination above FDA levels," he posted. "No kidding."
Mr Musk's reference to the Food and Drug Administration is not strictly correct: though bottled water is regulated by the FDA, public tap water is supervised by the Environmental Protection Agency.
He then went on to explain in other tweets that he would pay for water filters for all houses that were able to show their water was unclean. And in the long-term he would help with other projects.
He also promised to try and help resolve a breakdown in trust between the authorities and residents in Flint, as well as organise a "barnstorming" event during which filters would be added to Flint houses that don't have access to clean water.
"Most houses in Flint have safe water, but they’ve lost faith in government test results," he wrote. "Some houses are still outliers. Will organise a weekend in Flint to add filters to those houses with issues & hopefully fix perception of those that are actually good."