As the rain picked up in intensity in the Red Hook district of Brooklyn, the circuit quickly became waterlogged and caused a flurry of incidents - with race leader Nick Cassidy dumping his Envision machine into the wall, where he was followed by Lucas di Grassi and Stoffel Vandoorne.
Meanwhile, Bird had been caught out by a stranded Pascal Wehrlein on the exit of the corner, but had managed to get rolling again.
