by Michelle Franzen
NBC News

A massive manhunt is underway to find a robber who brazenly killed two armored car guards Thursday morning in Philadelphia.

Witnesses say the sound of gunfire came out of nowhere.

Police say a lone robber killed the two armored car guards, injured a third and then fled in a black sedan.

"We're looking for an armed and dangerous male who has no regard for human life," said Philadelphia Police Commissioner Sylvester Johnson.

The FBI called it a cold-blooded assassination.

Guarding millions in cash is an increasingly dangerous business.

In September robbers in Dallas made off with a million dollars from a Loomis armored truck.

This summer Brinks armored cars were the target in several robberies in Miami.

Last year there were 37 armored car robberies.

This year is expected to be the worst in five years.
The two armed guards killed Thursday were retired police officers William Widmaier and Joseph Allullo, lifelong friends who worked and died together.

The third guard was grazed by bulletproof glass when he was fired upon.