There was a liner built for the Europe/South America trade named Magdalena, which grounded and broke in half on her maiden voyage, ca 1950. The wreck was well photographed and finding links to views of this disaster from which- fortunately- everyone escaped, should not prove difficult.
The Mohawk, although not a new liner, sank 6 hours into her maiden voyage for the Ward Line.
The Zenobia cargo ship/car ferry (I've heard her called both) committed suicide on her maiden voyage, but no one died on her, I don't think. I think her ballast machinery went haywire and she suddenly began flooding her port side. I think there was a liner called the Principessa Yolanda (or something close) that sunk like a stone as soon as she was launched.
Not a sinking, but the French Line's "M.S. Flandre" experienced terrible power interruption on the maiden voyage, which colored her career ever after, in spite of a long life into cheapo cruise line service. I think she's scrapped now. Among those who patronized this vessel was Gypsy Rose Lee, famous American stripper.
Going slightly back in time, there was the Vasa which was built as the new and putting-every-other-ship-in-the-shadow flag ship of the Swedish navy. This is what the Vasamuseet has to say about it:
"In 1628 the ship was ready. Sunday August 10 was the day of the Vasa's maiden voyage. The beaches around Stockholm were filled with spectators, among them foreign diplomats. The maiden voyage was to be an act of propaganda for the ambitious Swedish king Gustavus Adolphus.
"The Vasa set sail and fired a salute. But only after a few minutes of sailing the ship began to heel over. She righted herself slightly - and
heeled over again. Water started to gush in through the open gunports. And, to everyones horror and disbelief, the glorious and
mighty warship suddenly sank! Of the 150 people on board, 30-50 died in the disaster. When Vasa had been salvaged in 1961, archaeologists found the remains of 25 skeletons."
That's what we today call a public relations disaster.
Don't forget the spectacular tale of the Principessa Jolanda which was all but completely fitted out on the ways and which was launched in front of thousands...including members of the Italian nobility.
What does she do?
She slid into the water, she rolled over onto her starboard beam and, she sank on the spot!
That would appear to be the case. If I recall correctly, there were issues with the construction of the ways being done at too steep an angle as well. Launching a ship has always been a risky operation. Get the weights and balance wrong or miscalculate the angle of the ways and you just might find yourself looking for a new job.