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5 things for April 4: YouTube, tariffs, midterms, oil spill, Martin Luther King Jr.

(CNN) It's a somber morning in California, and a somber day around the country: Today is the 50th anniversary of the assassination of Dr. Martin Luther King Jr. Here are some ways you can honor him today, along with everything else you need to know to Get Up to Speed and Out the Door. (You can also get "5 Things You Need to Know Today" delivered to your inbox daily. Sign up here.)

1. YouTube shooting

We're still learning about yesterday afternoon's shooting at the YouTube headquarters near San Francisco. A female shooter opened fire, injuring three people before killing herself with a handgun. The shooter has been identified as 39-year-old Nasim Najafi Aghdam. Police still aren't sure of a motive and say they know "very, very little right now." They say there's no evidence that she knew the victims or that anyone was specifically targeted.

The YouTube headquarters is home to 1,100 employees. After the incident, the tech giant released a statement, saying, "It feels like the entire community of YouTube, and all the employees were victims of this crime."

2. Tariffs

China and the US are escalating their tariff trade-off, and the situation isn't pretty. After China this week enacted tariffs on $3 billion worth of American goods -- in response to President Trump's tariffs on steel and aluminum imports -- the US proposed tariffs on $50 billion worth of Chinese goods. That includes 1,300 possible imports chosen after a monthslong US investigation into theft of intellectual property and trade secrets. The latest round of tariffs could go into effect next month.

Chinese goods that may be subject to tariffs:  

Aerospace and marine equipment: Air combat flying simulators, airplane parts, helicopters, tankers, ferries and fishing boats

Manufacturing: Bookbinding machines, brewery machines, concrete mixers, hand-held blowtorches, milking machines, nuclear reactors, snowplows

Medical supplies: Artificial body parts, artificial teeth, catheters, dental fillings, hearing aids, vaccines for humans and animals 

Other: Artillery weapons, cash registers, fire extinguishers, flamethrowers, seismographs

3. Midterm elections

After the Democratic-backed candidate won a seat on Wisconsin's Supreme Court, the state's Republican Gov. Scott Walker fired off a tweet storm warning that the GOP is "at risk of a #BlueWave" in November. Tuesday's victory was the first time a liberal candidate who wasn't an incumbent had won a seat on Wisconsin's seven-member court in 23 years. That, and a major swing in Democrats' favor in a Wisconsin Senate race this year, may be indications of changing political leanings -- after all, Donald Trump and GOP Sen. Ron Johnson won big there in 2016. And it's not just Wisconsin. In Virginia, Oklahoma, Alabama and New Hampshire, seats long held by the GOP have recently flipped to Democrats.

4. Oil spill

Indonesian authorities have declared a state of emergency over an oil spill off the Southeast Asian country's coast. The spill has been spreading for almost a week, wreaking environmental and economic havoc. It's also been blamed for the deaths of four fisherman. Video shows parts of the spill catching fire, and authorities are warning people to keep open flame away. People reportedly were having trouble breathing and experiencing nausea and vomiting since the fires broke out. Indonesian authorities say they aren't sure what caused the spill. 

5. Martin Luther King Jr.

On this day in 1968, Martin Luther King Jr. was shot and killed on a motel balcony in Memphis. It is a tragic anniversary that conjures up so many questions: 50 years after his death, what does King's legacy mean today? How do his politics speak to our timeWhat would our country be like if only had he lived

BREAKFAST BROWSE

People are talking about these. Read up. Join in.

How can we record our dreams?

This sounds like a good idea -- until you have that one where you show up to work in your underpants.

The Hubble telescope discovered the farthest single star ever seen

Its nickname is "Icarus." Have fun dissecting that one, mythology pedants.

This intense video appears to show snow, but it's actually ... pollen

Warning: Your eyes may water just looking at it.

Bed Bath & Beyond will exchange your Toys 'R' Us gift cards

Which makes sense, because Bed Bath & Beyond is just a toy store for people who love linens and aromatherapy diffusers.

New dinosaur tracks have been discovered in Scotland

This can only mean one thing: The Loch Ness Monster is real, y'all!

TODAY'S NUMBER

10 million

The weight, in pounds, of biowaste (poop) that the mayor of Parrish, Alabama, says has been rotting since January in the rail yard of her small town

AND FINALLY

Pay no attention to the man on the dumbbells.

All that work, only to get overshadowed by a senior citizen draining free throws. (Click here to view.)

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