An earthquake of magnitude 6.4 struck north of Puerto Rico on Monday, the U.S. Geological Survey said. The quake was very shallow, at a depth of 17.7 miles below the seabed. It struck at 12:01 a.m. (0401 GMT), 35 miles north of the town of Hatillo. The Pacific Tsunami Warning Center initially said the quake could trigger a small local tsunami. But the U.S. National Weather Service Caribbean Tsunami Warning Program determined that no tsunami was generated. Sunday marked the fourth anniversary of the devastating 7.0 magnitude earthquake in nearby Haiti that left more than 200,000 people dead and left 1.5 million homeless.
