An evacuation order remained in effect Wednedsay night for about 250 homes in the Littlerock area, near Palmdale.
That, after a freight train derailed Wednesday afternoon.
Between 50 and 100 cars went off the tracks near 92nd Street East and East Avenue T about 1:25 p.m., said Inspector Matt Levesque of the Los Angeles County Fire Department.
No injuries were reported.
Some of the cars were believed to be carrying hazardous materials, but Wednesday night, authorities did not believe there were any leaks.
Union Pacific officials said the train only had six cars that would have contained hazardous materials.
An evacuation, effecting around 250 homes was ordered as a precaution, according to County Fire.
"It is pretty sparsely populated up there, probably it is affecting only homes directly next to the train. The evacuations are just a precaution," Levesque said.
More than 20 of the cars were off the tracks or overturned.
Levesque said it could take hours upright the cars and determine if there actually are any chlorine leaks, given the number of cars in the train and the need to inspect each individually.
The cause of the derailment was not immediately known, although the train did not strike any vehicles.
