Thanks Nick,
I found several files describing the battles of 10th Mountain Division here:
http://www.sulleormedeinostripadri.i...-division.html
There reports are quite detailled. For example, the 87th Regiment's history has 6.5 pages on 3 March 1945, and I think all men KIA or fatally wounded that day are listed by name. The 86th history provides less details, but still had 5 pages on 3 March 1945 and gives the names and loss circumstances of 6 men. I could find 8 more on ABMC and FindaGrave databases. The 85th was in reserve and only lost 1 KIA and some WIA.
An air attack leaving 14 dead and 24 wounded would certainly have been noticed in these reports, as it will be a significant part of the day's casualties. But there is no mention of it in any of the documents available on the site above.
By the way, I found 14 dead for 86th Mountain Regiment for the whole day, not just one incident, and I wonder if the veteran did not mix things and is attributing the whole day losses to the incident that crippled him.