@LASchools closed today regarding unspecified threat. #LASD #LAPD and #LASPD Investigating.

— LA County Sheriff's (@LASDHQ) December 15, 2015

UPDATE, 1034am PT: NYPD commissioner Bill Bratton says NYC got the same threats as LAUSD did, and determined it to be a hoax. Bratton says LA authorities are massively overreacting. LAPD Chief Charlie Beck disagrees.

Wouldn't be a Tuesday in America without an incident of mass violence or a threat of one.

“Officials closed all Los Angeles Unified School District campuses Tuesday morning after receiving a 'credible threat' of violence involving backpacks and packages left at campuses,” the Los Angeles Times was among the first to report today. LAUSD is America's second-largest school district, with more than 700,000 students. Read the rest

At least twenty people are dead following an explosion in Bangkok, "reports the BBC—but footage from the scene already offers a suspect. 

Videos taken by nearby CCTV and tourists show how the blast hit a crowded shrine in Thailand's largest city.

Police are now hunting the yellow-shirted man seen dumping a backpack at the site of the blast.

In the new footage, he is shown carefully and deliberately removing his backpack inside the shrine, getting up without it and immediately leaving the scene. The spot where he was sitting is precisely where the bomb went off a few minutes later, says the BBC's Jonathan Head in Bangkok.

"There is a suspect... we are looking for this guy," Prime Minister Prayuth Chan-ocha told reporters. Authorities were "quite close" to identifying the suspect, Thai government spokesman Maj Gen Weerachon Sukhontapatipak told the BBC, but other leads were also being pursued.