SAN ANTONIO -- Bexar County Judge Nelson Wolff called on federal officials Monday to put pressure on Union Pacific Railroad to operate more carefully in San Antonio.

"We've got to get their attention," Wolff said in an interview with KSAT 12 News. "That could mean raising a little hell."

Wolff's comments came three days after two freight trains collided on the South Side, derailing 27 cars, the third train derailment in a year. The Burlington Northern Sante Fe and Union Pacific trains collided about 11 p.m. Friday, derailing the cars and spilling magnesium chloride from one car. There were no reported injuries and no one was evacuated from their homes as of early Saturday morning.

In June, a Union Pacific train derailed near the location of Friday night's derailment. Three people died in that accident.

In May, a Union Pacific Railroad train derailed and spilled thousands of gallons of diesel fuel the San Antonio River at Roosevelt Avenue and South St. Mary's St.

Wolff said Friday's accident, just south of downtown, could have resulted in more hazardous cargo being spilled into nearby neighborhoods.

"That was pure luck," Wolff said.

Consulting maps showing where rail lines could be re-routed away from populated areas, Wolff said it could take years and millions, if not billions, of dollars in government and railroad company money to change track locations.

In lieu of moving the tracks, Wolff said he wants action now over safety issues.

"We're telling you, you better step up your safety measures," Wolff said. "You better get better trained people on the ground. If you're blaming this on a transient that unhooked your cars, then where is your security?"

U.S. Rep. Charlie Gonzalez, of San Antonio, echoed Wolff's call for better safety measures.

"What is the railroad doing about their equipment, their training, and their personnel?" Gonzalez said. "We're going to demand answers, but we really do need (an) investigation to be complete before the railroads are going to come forward and address these particular problems."

A Union Pacific spokesman contacted said the company shares the city's concerns.