NASA's Antares rocket, headed to the International Space Station, exploded shortly after launch Tuesday night.
The rocket was unmanned, and NASA officials said no personnel appeared to be in danger.
However, there was "significant" property damage.
The explosion lit up the sky at the launch pad in Virginia and occurred about 6 seconds after liftoff.
The Orbital Sciences Corp.'s Antares rocket and Cygnus cargo spacecraft were set to launch at 6:22 p.m. ET. It was set to carry some 5,000 pounds of supplies and experiments to the International Space Station.