Seven Marines are dead. Several more seriously wounded. The result of an apparent training accident in Nevada.
 
Senate Majority Leader Harry Reid rushes to the Senate Floor to...try to exploit the deaths as a political weapon in the partisan dispute over the Sequester.
 
From the AP account of the tragedy:
 
The explosion occurred Monday night at the Hawthorne Army Depot, a facility used by troops heading overseas, during an exercise involving the 2nd Marine Expeditionary Force from Camp Lejeune, N.C. Several Marines from the unit were injured in the blast, authorities said.

The mortar round exploded in its firing tube during the exercise, said Brigadier General Jim Lukeman at a news conference at Camp Lejeune. He said investigators are trying to determine the cause of the malfunction.

Lukeman extended condolences to the families of the victims. "Our first priority is to provide them support and we're doing that now," he said.

The Marine Corps said in a statement that it suspended all use of high-explosive and illumination mortar rounds that were in the same manufacturing lots as the ones that were fired in Nevada. The Pentagon suspended use of those rounds worldwide across all branches, not just the Marines.

The Marines were also considering a stop-usage order affecting the mortar tubes like the ones in the accident.
It was not immediately clear whether more than a single round exploded, a Marine Corps official said, speaking on condition of anonymity because the official wasn't authorized to speak about an ongoing investigation.
 
 
Harry Reid's comments, courtesy of Real Clear Politics:

Mr. President, it's very important we continue training our military, so important. But one of the things in sequester is we cut back in training and maintenance. That's the way sequester was written. Now, the bill that's on the floor, we hope to pass today helps that a little bit. At least in the next six months, it allows the military some degree of ability to move things around a little bit. Flexibility, we call it, and that's good. But we have to be very vigilant. This sequester should go away. We have cut already huge amounts of money in deficit reduction. It's just not appropriate, Mr. President, that our military can't train and do the maintenance necessary. 

These men and women, our Marines were training there in Hawthorne. And with this sequester, it's going to cut back this stuff. I just hope everyone understands the sacrifices made by our military. They are significant, being away from home, away from families, away from their country.
 
Harry Reid, far and away the Loser of the Day.