Kropp, who had the 10th-best prelim time of 2 minutes 14.91 seconds, competed in the semifinals of the 200 IM Wednesday evening, where she finished with the 10th-best time once again (2:14.44).
A top-eight finish would have been enough to advance her to today's finals. The top two swimmers from each event plus four more in both the 100 and 200 freestyles qualify for the 2012 Olympics, set for July 27-Aug. 12.
Kropp's bid to qualify in the 100 breaststroke also ended in the semifinals on Tuesday, but her most promising event lies yet ahead when she will go all out for a spot on the team in the 200 breaststroke, beginning Friday.
"I'm just swimming between two lane lines, it doesn't matter how many people are there or anything else," said Kropp, a two-time former All-Area Girls' Swimmer of the Year. "It's just a race I've done a ton of times and now I can really focus on that instead of the meet [itself]."
Crescenta Valley High senior-to-be Young Tae Seo competed in his second trials event on Wednesday, but again came up well short of advancing.
The reigning All-Area Boys' Swimmer of the Year, who led the Falcons to the CIF Southern Section Division II championship in May, had the 131st-best time in the 200 butterfly (2:08.68) after turning in the 91st-best effort in the 400-individual medley on Tuesday.