BRIGGS: Four-forty-six Eastern Time. And there are many unanswered questions this morning after hours-long gun battle ended in the deaths of four people including a police officer in Jersey City, New Jersey.</s>BRIGGS: The shooting began just afternoon and moved among three locations that drew officers from neighboring departments. Businesses in the areas were shut down. Schools went on lockdown. The fallen officer was Detective Joseph Seals, a 15-year veteran of the department. He was part of the statewide antiviolence unit credited with removing guns from the street.</s>GOV. PHIL MURPHY, NEW JERSEY: There are days that require us to stop and think about what it means to put on a uniform every day, and God knows this is one of those days. If not for them, I shudder, we shudder to think of how much worse today could have been.</s>ROMANS: Police say the bodies of three victim and two suspects were found inside a kosher grocery store. Jersey City's mayor says based on an initial investigation, the shooters targeted that location, but he did not offer further explanation. New York Mayor Bill de Blasio directing the NYPD to redeploy assets to protect key locations in the Jewish community. Two officers and one civilian were in stable condition after being shot. Jersey City public schools will open at 10:00 a.m. today.</s>BRIGGS: Bad news for coastal cities around the world. A new study says Greenland's ice sheet is melting at a rate five times faster than the 1990s. The study in the journal "Nature" found that Greenland's ice sheet is melting fast enough now to raise sea levels by about 0.7 of a millimeter a year. That may not sound like much, but 100 million people currently live below the high tide expected in the year 2100. So even small rises in sea level could have catastrophic effects on coastal communities.</s>ROMANS: All right. Forty-eight minutes past the hour. Still searching for a Christmas present? What about a new computer for the bargain price, oh, $52,000? CNN Business is next.
Four Killed in Jersey City Rampage