Activists said most of the casualties were in the Khalidiya quarter of Homs, which they said came under massive bombardment by security forces in the middle of the night. They said victims were still being dug out of the rubble of collapsed buildings. Video posted on the Internet showed many bodies sprawled in pools of blood. The reasons for the sudden reported escalation weren't immediately clear. Parts of Homs have become virtually no-go areas for government forces with rebel fighters from the Free Syrian Army well entrenched.

 

The BBC's Jim Muir.

 

Four inches of snow brought the Italian capital to a standstill, shutting schools, museums and public offices. NPR's Sylvia Poggioli reports it's the biggest snowfall in 26 years.

 

Crowds of Romans and tourists were walking cautiously on slippery streets, but there was a mood of excitement over the unusual sight, St. Peter's dome, the Colosseum and Roan Forum covered in snow. But the snowfall and low temperatures caused much disruption. Lack of snow plows left many drivers trapped in their vehicles for up to ten hours on the ring road circling Rome, and snow-covered streets led to traffic jams and long bus service delays. The snowfall had been forecast for days, but many Romans blame City Hall for lack of preparedness. Mayor Gianni Alemanno ordered 2,000 shovels to be distributed and appealed to residents to chip in and help clean up streets and sidewalks. Sylvia Poggioli, NPR News, Rome.

 

The snow is letting up in Colorado after the most powerful storm there this winter. The Rocky Mountain foothills received as much as six feet of snow. About 600 flights were canceled in Denver.

 

Republicans in Nevada are voting today on a nominee for president. Polls show that Mitt Romney will win as he won that state's caucuses four years ago. NPR's Carrie Kahn has been talking to people attending a caucus at a retirement community in Henderson. 

 

A lot of people are undecided. Many people are favoring Romney. I heard that a lot. But then you have some people say that they just want to come in and give a protest vote because they don't believe that he should be the nominee. But then one thing that you hear from everybody is that whoever the nominee is, they will unite around them because they are all unified in wanting to defeat Obama.

 

NPR's Carrie Kahn reporting from Henderson, Nevada. After the voting, Romney is to hold a party for supporters at a casino in Las Vegas. His closest challenger Newt Gingrich is not holding a public event tonight, but will issue a statement after the results are announced.

 

This is NPR News from Washington.

 

Officials in Northern California say propane gas exploded in an area housing Marine Corp families last night. One person was killed, and two others were injured. The blast occurred in Coleville, about 30 miles from the Marine Corp Mountain Warfare Training Center, where Marines train for mountain operations. Thirty-eight families were forced out of their homes because of the lack of utilities. Officials say they don't know yet why the propane gas leaked and then ignited.

 

The rocket scientist who tried to stop the fatal launch of the space shuttle Challenger has died. Roger Boisjoly led a group of Morton Thiokol engineers who argued with NASA officials the night before the launch that cold temperatures could lead to a catastrophe. NPR's Howard Berkes reports.

 

Roger Boisjoly was so destroyed about the explosion of the space shuttle Challenger. He suffered depression and severe headaches. All he could do at one point he told me at the time was move boulders around his yard for therapy. Boisjoly and four other Thiokol engineers argued vigorously with their own managers and NASA officials the night before the launch. They presented data indicating that coldest launch-time temperatures ever would stiffen seals in the joints of the multi-stage booster rockets. When the spacecraft exploded, Boisjoly told NPR, "We knew exactly what happened." Roger Boisjoly was 73 and suffering from cancer in Utah when he died. Howard Berkes, NPR News, Salt Lake City.

 

US Park Police on horseback moved into a park near the White House early this morning to enforce a no-camping ban. Protesters connected to the Occupy movement have been living in McPherson Square for months. Some of the protesters removed their camping gear. Six people were arrested. Officials say this is not an eviction. The protesters have the right to be in the park at all hours, but they can't sleep there.

 

I'm Nora Raum, NPR News in Washington.