Parts of a Learjet may have broken off midair before Florida crash that killed 9, investigators say

WEST PALM BEACH, Fla. (AP) — A business jet that crashed in Florida and killed all nine people aboard, including a family with two young children, likely started breaking apart before it slammed into the ground and erupted in a fireball, a federal investigator said Monday.The jet did a steep nosedive, leaving behind a crater and a wide debris field as rain pounded the area. Authorities said weather will be a key initial focus of the investigation, and that the National Transportation Safety Board will also examine the actions of the crew and look for any mechanical problems with the plane.The plane burst into flames when it crashed in Greenacres, about 7 miles (11 kilometers) southwest of West Palm Beach. Thick black smoke engulfed the crash site and little remained of the plane.The victims included the 20-year-old co-pilot, Nathalia Gadelha Filgueiras, who made the final radio transmissions, as well as technology entrepreneur Adam Robinson, his wife, Helen Sharp, and their two young c