Much of the Houston Ship Channel remained closed Saturday a day after two vessels collided, causing a large gasoline blend spill and setting off another round of environmentalists concerns for the Gulf Coast.

The 755-foot tanker Genesis River carrying liquefied natural gas collided Friday afternoon with a tug boat pushing two barges, each carrying 25,000 barrels of product, around 3:30 p.m., the U.S. Coast Guard said.

One barge capsized and the other was damaged, leaking a gasoline product called reformate.

The channel closure is the first unplanned shutdown since March, when a massive chemical storage tank fire at Intercontinental Terminals Co., in Deer Park spilled petroleum products into nearby waterways. That three-day closure cost the energy industry about $1 billion, experts estimated.