GALVESTON, Texas -

The Coast Guard and National Transportation Safety Board are holding a hearing to determine the cause of an oil spill from March 22.

The collision dumped more than 160,000 barrels of thick crude at the mouth of the Ship
Channel.

It fouled beaches as far south as Matagorda Island, coated hundreds of birds and other wildlife and forced the closure of the ship channel for three days.

The oil gushed from a barge towed by the tug Miss Susan. It had collided with a cargo ship, the Summer Wind.

According to today's testimony, the tow ship was traveling across the channel bound for Bolivar from Texas City with the oil barge. The Summer Wind was headed out of the channel.

One of two witnesses today, Brent May, was the navigator on another ship plying the channel that day. He said the visibility was limited by thick fog. He said in spite of that, the Summer Wind appeared to speed up as it closed with the tug.

May said he and other ships had been in touch with the Miss Susan by radio, but he said he didn't hear the tow boat and Summer Wind talking to each other until it appeared they might collide.

Tuesday, the captains of the two vessels are being called to testify which should provide the first detailed, public explanation of how it happened and why.

The costs of the cleanup after the spill were paid by the barge owners, Kirby Inland Marine of Channelview.

The Coast Guard says the hearings now underway in Galveston are not intended to determine criminal or civil liability.