Jeff Dedon was always nervous about the trains that three times a day rumble by his car repair shop on South Choctaw Drive, where he has worked for more than 30 years.

His fears were confirmed shortly after 9:30 a.m. Friday, when seven train cars derailed outside his business, Car Master Inc., near North Sherwood Forest Drive. He watched the cars crash into each other and flip over the side of the tracks, warping the rails and sending pieces of wood, iron and dust into the air. By the time the train screeched to a halt, seven cars were sprawled across the tracks or partially dug into the ground.

The cause is still under investigation, but no one was injured and no dangerous chemicals were leaked, said Patrick Waldron, a spokesman for Canadian National Railway Co. The derailed cars were holding fiberboard, silica pellets and lube oil; one empty tank carried the residue of a toxic chemical called difluoromethane, he said, but that chemical did not leak.

As the Baton Rouge Fire Department worked to right the train cars, police closed the roadway from North Sherwood Forest Drive to Monterrey Boulevard through Friday afternoon, said Cpl. Don Coppola, a police spokesman. Police were hoping to reopen two of the lanes on South Choctaw Drive within hours, through cleanup was projected to finish late Friday evening.

The train’s 105 cars carried a range of merchandise and general freight, and were heading east from Baton Rouge to Jackson, Mississippi, Waldron said. He declined to say whether any other cars were carrying toxic materials.

“This had always been on my mind as something that could happen,” said Dedon, who was working on a car with a customer standing alongside him when he heard screeching and ran out to the front of his shop.

Michael Davis also was standing outside his shop, Allstate Auto on South Choctaw Drive, when he saw train cars flip and fall over from about 60 yards away.

“It was kind of like slow motion,” he said.

There was no mandatory evacuation of the area, but some businesses decided to close, said Mark Miles, a Baton Rouge Fire Department spokesman. The department’s Hazardous Materials Unit is also investigating.

Employees of Merck Animal Health were briefly unable to leave their Dual Street location off South Choctaw Drive after being walled in from the lane closures, said Kelly LeDuff, whose wife works at the business.

LeDuff, who also said he was a senior trainmaster in Baton Rouge until June, added that the Merck employees were panicked about a possible toxic spill and should have been told what was happening sooner.

“The community deserves to know what went wrong,” he said. “The people who work in this area shouldn’t be terrified every time a train comes down the tracks.”

Follow Daniel Bethencourt on Twitter @_dbethencourt