As it was approximately halfway between the two separate leagues, the San Francisco region was a natural place for new teams to find a home, as was the case with the Fresno Falcons and Oakland Oaks.
The Shamrocks, along with the San Diego Skyhawks, asked the league for a 1-year hiatus in 1950 with the intent to return but the move proved disastrous for the club.
On February 6, 1947, midway through the team's third season, the Shamrocks were travelling to a game when their train slammed into a truck carrying gasoline in Fresno, California.
Though their issues were not considered life-threatening, the affected players (Roy McKay, Boyd Prentice, George DeFelice, Rolly Morrisseau, Sid Lovelace and Ralph Orlando) missed the remainder of the season.
In order to help the team, each of the other clubs in the PCHL's Southern Division agreed to send a player to San Francisco so they could finish out the season with a full roster.