Radio and television stations interrupted programming for 30 seconds today as the U.S. conducted the first national test of a disaster-warning system.

The test of the Emergency Alert System was scheduled for 9 a.m. Hawaii time on broadcast and satellite television and radio and cable TV, according to the U.S. Federal Emergency Management Agency.

Officials say they timed the test to avoid rush-hour disruptions. They say the date was picked because it’s near the end of hurricane season but before the arrival of winter.

For 50 years, the U.S. has had an alert system under various names that has been used regionally to provide information about severe weather and other emergencies.

The national test is “the first step” in identifying the system’s failings so they can be fixed, FEMA Administrator Craig Fugate and Federal Communications Commission Chairman Julius Genachowski wrote in a letter last week to governors and private-sector groups.

A national alert could be used to warn of a nuclear attack or other national disasters, said Rachel Racusen, a FEMA spokeswoman.

In preparing for the test, U.S. officials already found the system couldn’t run closed captioning for the hearing impaired, translations and, in the case of some cable TV channels, visual warnings to accompany the announcements, Fugate and Genachowski wrote.