Short answers, pulled from the story.
Antipater of Sidon wrote an inscription listing seven marvels during the 2nd to 1st century BC. He described seeing the wall of Babylon and the statue of Zeus by the Alpheius river.
The Colossus of Rhodes was completed after 280 BC but destroyed by an earthquake in 226 or 225 BC. It remains the first wonder to be lost among all seven entries.
Sculptures from the tomb of Mausolus currently reside in the British Museum in London. Excavations have uncovered remains of the site either in situ or displayed in museums.
No physical trace has been found despite extensive searches in Iraq according to Irving Finkel's 1988 study. Stephanie Dalley traced possible locations to Hillah or Nineveh in her 2013 book The Mystery of the Hanging Garden of Babylon.
All seven wonders existed simultaneously for less than 60 years before the first fell. The Great Pyramid of Giza remains standing while all other original wonders have been destroyed over centuries.