ST. LOUIS (AP) — Roughly 300 gallons of crude oil spilled early Friday into the Mississippi River near St. Louis after a vessel on the rain-swollen waterway slammed into a fleet of docked barges, causing 14 of them to briefly break away, according to the Coast Guard.

None of the oil was found to have washed up on the river’s banks as of mid-morning Friday, though crews still were assessing the possible environmental fallout of the spill — the equivalent of seven barrels — and the precise cause of the accident about 1 a.m. near Alton, Ill., Coast Guard Lt. Colin Fogarty said.