Santa Barbara police opened an investigation after 27 people who ran a half-marathon Sunday sought care at Cottage Health emergency rooms in Santa Barbara and Goleta for symptoms the hospital and police described as unusual^2,7.

Cottage Health said 24 of those patients were treated and released and three remained hospitalized in stable condition as of Monday^2,7.

The race, sponsored by Hoka and organized by Run Local, drew several thousand registered runners along a 13.1-mile course by the Pacific and through downtown^2,4.

Event director David Monico said medical staff treated numerous runners for dehydration and overheating on the course and at the finish, and that some were taken to hospitals².

Santa Barbara County Health said Monday night the episode appeared isolated to race participation and heat, with no sign of a broader public-health risk, according to Advance Local reporting^4,5,6.

The same accounts said inspections of hydration areas found no violations, after online speculation that water stations might have been contaminated⁴.

Monico declined to comment to the Los Angeles Times on those rumors; runners the Times interviewed said they drank at stations and did not fall ill².

KTLA reported that emergency crews first answered a call about 8:41 a.m. for a runner feeling faint, then more runners asked for help, and that officials said spectators did not report matching symptoms⁷.

An unidentified hospitalized runner told KEYT, as relayed by KTLA, they were unconscious for nearly an hour and did not remember part of the run⁷.

Outlets differed on the day’s heat: the Times cited a National Weather Service noon reading of 86 degrees versus a typical high near 71, while KTLA cited a high of 82 and Advance Local cited about 80^2,4,7.

Police have not said they have established a crime; KTLA reported they had not confirmed the matter was criminal, and Advance Local said the inquiry remained open with a sergeant listed for tips^4,7.