A huge federal probe was under way Tuesday into what caused the deadly LA wildfires, with millions in the city clamoring for answers. Social media has exploded with theories about what started blazes that tore through the city of Altadena and the upmarket neighborhood of Pacific Palisades, killing at least 24 people and leaving communities in ruins. Suggestions include downed power lines, deliberate arson, a stray firework and the reignition of an earlier fire. The ATF is working with local law enforcement, as well as the Forest Service and the US Attorney's office, in an operation that will involve around 75 people.

SEE THE TOP THEORIES ABOUT THE ORIGINS OF THE FIRES

Lunar landers built by US and Japanese companies were poised to "rideshare" to the Moon, showcasing the private sector's growing role in space exploration. SpaceX targeted a Wednesday liftoff of a Falcon 9 rocket from the Kennedy Space Center in Florida. On board are two privately developed, uncrewed lunar landers: Firefly Aerospace's Blue Ghost and ispace's Resilience from Japan. Both aim to build on the success of Texas-based Intuitive Machines, which last year became the first company to successfully touch down on Earth's celestial neighbor.

SEE WHAT SCIENTISTS HOPE TO LEARN FROM DUAL MISSION

Starbucks has stirred the coffee pot by reversing a policy that allowed anyone to use its bathrooms, with the US public warned they'll need to buy something or get out. In a new code of conduct, the hot drink behemoth that boasts 29,000 retail stores in 78 markets said it wanted "to ensure our spaces are prioritized for use by our customers." That includes the chain's cafes, patios and restrooms, according to the policy, which Starbucks noted is something most retailers enforce.

BUY SOMETHING OR LEAVE: SEE WHY STARBUCKS SWITCHED

When and where did Starbucks open its first store outside the US? 

Tuesday's answer: The 1957 kidnapping and murder and kidnapping of Illinois 7-year-old Maria Ridulph is the nation's oldest solved cold case.