A railroad boxcar filled with ammonium nitrate lays on its side near to the remains of the fertilizer plant that exploded the day prior in West, Texas. - 

After the fertilizer plant located near a school in West, Texas exploded last month, Associated Press reporter Jack Gillum got to thinking, where else in America is there ammonium nitrate stored in vulnerable areas?

Federal law says this information should be a matter of public record, but citing terrorism fears, authorities in many parts of the country wouldn't tell him. Of the 28 states that did have data, the AP found 120 facilities near schoolchildren, the elderly and people with disabilities.

Gillum joins Marketplace Morning Report David Brancaccio to discuss his findings.

Follow David Brancaccio at @DavidBrancaccio