At T-6 seconds the second first stage engine failed before falling back onto the launch pad, there are no causalities known at the time of writing this.
The very first Antares 130 rocket, with an upgraded upper stage, was due to launch for the first time from Wallops Flight Facility in Virginia today, October 28th 2014 at 22:22 UTC. The rocket was carrying the Cygnus CRS-3 unmanned spacecraft due to go into orbit carrying 2,215 kg of cargo for the 6 crew members of Expedition 41 currently onboard the International Space Station.
NASA TV
<a rel="nofollow" class="external free" href="https://www.youtube.com/watch?v=aL5eddt-iAo">https://www.youtube.com/watch?v=aL5eddt-iAo</a>