<a href="mailto: pzekman@cbs.com; mhlebeau@cbs.com; dlblom@cbs.com" target="_blank">Send Your Tips To Pam Zekman</a>By Pam Zekman

(CBS) — They’ve been called rolling bombs: railroad tanker cars full of combustible liquids like crude oil.

The Chicagoland area is the No. 1 corridor in the nation for the transport of hazardous materials like crude oil, ethanol and other flammable chemicals.  And that leaves a lot of people worrying about the worst-case scenario, CBS 2’s Pam Zekman reports.

Forty-seven people died in Canada when a train loaded with crude oil derailed,  and earlier this year a tanker car fire near Galena burned for days.

The images haunt leaders of communities with heavy rail traffic such as Barrington, where 20 freight trains with crude oil pass every day

“If it happens in the middle of my town, 10,000 people live here, 8 percent of the homes are within 300 feet of the tracks,” Barrington Village President Karen Darch says. “It would be an absolute devastation.”

The federal government recently issued new safety standards for tanker cars in hopes of preventing future catastrophes.

“The standard for a new tank car is a good one. The problem is, it’s not going to apply to enough cars and soon enough to make a difference for our community,” Darch says.

Current, less safe tankers can still be used for another 10 years — for liquids like Ethanol, or if there are less than 35 tanker cars per train.

In southwest suburban Steger, dozens of crude oil trains pass through each day.

“If we were to have an accident right here at this crossing, you would wipe out half of Steger,” Frank Elton of Bambino’s family restaurant says.

This is also an issue in heavily populated Chicago, where rail lines crisscross the city.

Every day more than 450,000 gallons of crude oil roll through residential areas like this one in Pilsen.

Glenwood Fire Chief Kevin Walsh heads up a 34-town emergency response team. Every year, they send members to train at seminars paid for by the railroad industry.

“If we didn’t have a training like that, I don’t know if we could realistically prepare ourselves for an emergency of a crude oil or a train crash,” South Holland Fire Lt. Scott Stegenga says.

U.S. Sen. Dick Durbin, D-Illinois, is pushing the rail industry to adopt a faster timetable for replacing less-safe tanker cars.

“I fear the worst,” he tells Zekman.

Another concern with the tanker cars is accidental spills or leakage. Last year in Illinois, 4,146 gallons of hazardous materials either leaked or spilled out of tanker cars. That was a near 4,000 percent increase over 2013.

Officials say the delay in replacing all tanker cars is to give the railroads time to replace their fleet at a reasonable expense.