NEWARK, N.J.: Newark International Airport was closed for several hours this morning after a Federal Express cargo jet crashed as it was coming in for a landing. Eyewitnesses said the plane slammed into the runway as it descended and then flipped onto its back, sending flames spewing from the fuselage as it skidded across the tarmac. Miraculously, the plane's two crew members and three passengers survived, scrambling out a side cockpit window as flames quickly enveloped the aircraft. All five people were taken to a nearby hospital, treated and then released, a company spokesman said. The jet, an MD-11 en route from Anchorage Alaska, crashed at about 1:35 a.m. this morning. By 8:00 a.m., airport officials reopened the runway for departing flights only. All incoming flights were diverted to other airports until cleanup crews could remove the heaps of smoldering debris which remained at the crash site. Airport officials were unclear when arriving flights would resume landing.