HOUSTON, Oct. 26 (Xinhua) -- A small plane crashed in south Texas on Monday, and all four people aboard were killed, aviation officials said.

    Before the crash, the pilot reported having difficulties in maintaining the plane's altitude due to turbulence, said Federal Aviation Administration spokesman Lynn Lunsford.

    The wreckage was found on a private ranch near Benavides in Duval County. "Law enforcement officials reported that the crash was unsurvivable," Lunsford said.

    The plane was en route from Uvalde, Texas, to Leesburg, Florida, when controllers at FAA's Houston Center noticed it was losing altitude. The plane vanished from FAA radar at around 12 a.m. Monday after the pilot reported encountering turbulence.