BILOXI (AP) — Investigators said Friday that a preliminary report on the train-bus crash that killed four Texas tourists should be ready within two to three weeks.

Meanwhile, Biloxi Mayor Andrew “FoFo” Gillich on Friday added a seventh railroad crossing to a list the City Council will vote on closing Tuesday.

However, it won’t be the Main Street crossing where a CSX Transportation train slammed into the tour bus. Instead it’s on a Delauney Street, a side street that Biloxi Chief Administrative Officer Mike Leonard told WLOX-TV is among the most dangerous crossings.

“It doesn’t get a lot of traffic, but it’s at a point where trains are usually moving pretty fast right through the middle of the city here,” Leonard said.

National Transportation Safety Board spokesman Peter Knudson said in a news release that board investigators concluded work in Biloxi and have returned to their normal offices. He also said investigators interviewed the bus driver Wednesday. The board is asking any witnesses, or anyone with pictures, video or other relevant information to contact Pete Kotowski, the investigator-in-charge by emailing witness@ntsb.gov.

Biloxi had already been planning to close six of its 29 railroad crossings in the city before the train hit the Echo Transportation bus, killing four and injuring dozens. The bus was filled with senior citizens who were on a tour of Gulf Coast casinos and other sights.

Most crossings slated for closure are within a block of another crossing. Biloxi has said it chose low-traffic streets that don’t run in front of public facilities. Cost of the work isn’t known yet.

Biloxi wants to build two new railroad crossings, but Gillich said CSX won’t allow any more crossings unless the city closes existing ones. Biloxi officials want CSX and the Mississippi Department of Transportation to pay for connector roads. They also want the railroad and the state to make the humps leading to crossings less steep.

“CSX likes to say the only safe crossing is the one that doesn’t exist,” Leonard said. “So, we’re going to try to make some crossings not exist, but we’re also aware that before we close a crossing, we’ve got work to do.”

Some worry about decreased mobility, though.

“They need to put lights on them. They need to keep them safe. But closing them? I don’t think it’s a good thing,” said Timothy French, who crosses the railroad tracks every day for his business.

A survivor told The Associated Press that the bus got stuck on the humped crossing. CSX has said changing street grades is up to Biloxi. Following the collision, Biloxi installed additional signs at Main Street and other crossings that have low ground clearance, where long buses and trucks have gotten stuck on the tracks because of the grade of the road.