LAS VEGAS - The horror that unfolded last night in Las Vegas is now being called the deadliest mass shooting in U.S. history.

At least 50 people are dead and more than 200 others injured.

Authorities say a gunman opened fire on a crowd of concertgoers across from the Mandalay Bay Resort and Casino. He was later shot and killed by police on the 32nd floor of the Mandalay. He's being identified as a 64 year old local man by the name of Stephen Paddock.

Clark County Sheriff's Department officials say they've apprehended "a companion" of the shooter's named Marilou Danley.

The mass shooting forced the closure of McCarran International Airport for a brief period. The airport is just east of the Mandalay hotel. There were reports of people at the concert trying to escape the gunfire by running onto an airport runway. The hotel was also virtually locked down following the shooting.