A federal trial is underway to decide if engineering firms that advised the city of Flint on water issues bear some responsibility for the water crisis.
The case involves four Flint children alleging permanent damage from drinking water contaminated with lead, after the city stopped using Detroit's water system and switched to Flint River water instead.
Attorneys for the plaintiffs say engineering firms that advised officials before and after the switch failed to tell the city and state to use chemicals to control corrosion to keep lead from leaching out of pipes.
But attorneys for the engineering firms say the city gave them false data indicating there was no lead problem.
They call the water crisis a massive governmental failure.
The trial will involve a great deal of highly technical testimony and could last for four months.
