Tires emit huge volumes of particles and chemicals as they roll along the highway, and researchers are only beginning to understand the threat. One byproduct of tire use, 6PPD-q, is in regulators' crosshairs after it was found to be killing fish.
John Dickerson reports on the first witness to testify in Donald Trump's criminal trial, why sharks are important for the health of the oceans, and which drugs are in short supply.
A photo taken two days after the sinking of the RMS Titanic apparently shows the iceberg that doomed the so-called unsinkable ship in 1912. CBS News' John Dickerson has details.