The US Coast Guard says an investigation into noises heard in the search for a submersible are "negative".
Banging sounds had been detected in the Atlantic where the sub went missing with five people on board.
Officials say an investigation "yielded negative results", and there's only enough oxygen to last until tomorrow.
Roger Mallinson was saved in the deepest submarine rescue in history - off the coast of Cork in 1973.
He's worried about the current situation:
"That it horrendous, I can't understand why they haven't transmitted some signal of some sort."
"I have a horrible feeling that something might be seriously wrong, that they aren't able to transmit a signal"
