*International aid effort to Nepal intensifies. *Street vendors return in capital Kathmandu. JHARIBAR/SINDHUPALCHOWK, Nepal, April 28- People stranded in remote villages and towns across Nepal were still waiting for aid and relief to arrive on Tuesday, four days after a devastating earthquake destroyed buildings and roads and killed more than 4,300 people.» Read More
Investigators appear no closer to finding a suspect but are learning more about the bombs used, reports CNBC's Scott Cohn.
CNBC's Eamon Javers has the latest details on a ricin-laced letter sent to Sen. Wicker's office. And, Clark Ervin, former Homeland Security Department official; and Clint Van Zandt, former FBI profiler, discuss whether Monday's bombing leaves major events such as sporting, more vulnerable to future attacks.
CNBC's Scott Cohn reports the type of devices used in Monday's bombing in Boston are beginning to emerge.
Bomb fragments are being reconstructed at an FBI laboratory, reports CNBC's Scott Cohn. And, Philip Mudd, New America Foundation, discusses the psychological impact of terrorism and how to avoid copycat attacks.
CNBC's Eamon Javers has the latest details on a ricin-tainted envelope sent to the office of Sen. Roger Wicker (R-MI). Sen. Jack Reed (D-RI) and Sen. Angus King (I-ME) discuss a poison-laced letter sent to Capitol Hill, as well the Boston Marathon bombings.
CNBC's Scott Cohn reports the FBI and state and local law officials are intensifying their probe into Monday's bombing at the Boston Marathon, recovering two pressure cookers packed with nails and other metals.
Security consultants say the entire calculus of protecting a marathon has changed, reports CNBC's Scott Cohn; and Gen. Barry McCaffrey, ex-National Security Council member, weighs in. "[These bombs] were not sophisticated foreign-made intelligence provided devices," says McCaffrey.
Former Mayor of New York City Rudy Giuliani, who guided his city through the Sept. 11 attacks, said any speculation in the case of the Boston marathon attacks would be a mistake.
Two explosions went off near the finish line of the Boston Marathon on Monday; 3 people died, and 176 people were hospitalized due to injuries, reports CNBC's Scott Cohn.
Social media has made an impact after the Boston bombings. There were more than 1.5 million tweets mentioning Boston just after 4:30 ET.
The tragedy at the Boston Marathon on Monday was a terrible reminder of our safety. David Ropeik, Ropeik & Associates, shares his opinions.
The finish line of a marathon is a high for runners, and of course that all changed in Boston yesterday, with CNBC's Scott Cohn.
The latest on the terror events in Boston and how the nation's capital is responding, with CNBC's Eamon Javers.
The deadly Boston Marathon bombings won't "change the way we live" in the United States, said Jack Jacobs, a retired U.S. Army colonel who received the Medal of Honor. "We haven't had attacks like they have in Europe."
President Obama expressed confidence the FBI and other agencies are investigating the deadly Boston Marathon bombing, reports CNBC's Bertha Coombs.
"There are no options taken off the table," said Michael Leiter, former Director of the National Counterterrorism Center, discussing how the bombings in Boston will impact domestic and global security measures.
CNBC's Bertha Coombs has the latest details on reopening of Boston's airport, as law enforcement officials continue to collect video from surveillance cameras and watch for a man seen leaving the scene after the blast.
We don't yet know who planned and executed this, said President Obama, but we will find who did this and bring them to justice. As we receive more information we will make sure to keep the American people posted, he added.
Arthur Hogan, Lazard Capital Markets, discusses what's likely driving the rebound in today's markets following the tragic events in Boston yesterday.
Large events around the globe are affected by the tragic events in Boston, reports CNBC's Tom Mackenzie.