Large Asteroid Explodes Above California

Discovery News, via nc links:

The source of loud "booms" accompanied by a bright object traveling through the skies of Nevada and California on Sunday morning has been confirmed: It was a meteor. A big one.
It is thought to have been a small asteroid that slammed into the atmosphere at a speed of 15 kilometers per second (33,500 mph), turning into a fireball, and delivering an energy of 3.8 kilotons of TNT as it broke up over California's Sierra Nevada mountains. Bill Cooke, head of NASA's Meteoroid Environment Office, classified it as a "big event."
"I am not saying there was a 3.8 kiloton explosion on the ground in California," Cooke told Spaceweather.com. "I am saying that the meteor possessed this amount of energy before it broke apart in the atmosphere. (The map) shows the location of the atmospheric breakup, not impact with the ground."
Cooke went on to say that the meteor likely penetrated very deep into the atmosphere, producing the powerful sonic booms that rattled homes across the region. According to Reuters, car alarms in Carson City, Nev., were even triggered.
After some rough calculations, Cooke has been able to estimate the mass of the incoming object -- around 70 metric tons. This was a fairly hefty piece of space rock. From this estimate he was also able to arrive at an approximate size of the meteor: "Hazarding a further guess at the density of 3 grams per cubic centimeter (solid rock), I calculate a size of about 3-4 meters, or about the size of a minivan."

According to these guys, there might be a large amount of platinum lying around somewhere in California.