There were no injuries reported to the 596 train passengers, who were released at the neighboring Palo Alto station, according to Caltrain.
A Palo Alto resident, Mr. Rockhold had grown up in Menlo Park and played water polo for Menlo-Atherton High School and the University of California, Los Angeles, said his wife, Anne.
Mr. Rockhold was an internationally ranked water polo referee who led games at Stanford University, the University of California, Berkeley and other institutions on the West Coast, she said.
Mr. Rockhold was also active within the local aquatics and fitness community. He was a swimming coach for the Stanford Masters Swimming team and the University Club of Palo Alto; an instructor at Pilates V; and a personal trainer at Vivre Fitness, which recently closed, according to his LinkedIn.com profile.
He was also a volunteer assistant water polo coach at Palo Alto High School from 2008 to 2011.
"We are very sorry to hear about the passing of longtime water polo referee Craig Rockhold," USA Water Polo said on its Facebook page. "Our thoughts are with his family and friends during this difficult time."
Any person who is feeling depressed, troubled or suicidal can call 1-800-784-2433 to speak with a crisis counselor. Spanish speakers can call 1-888-628-9454.
People can reach trained counselors at Crisis Text Line by texting 741741.
This story contains 272 words.
Stories older than 90 days are available only to subscribing members. Please help sustain quality local journalism by becoming a subscribing member today.
If you are already a subscriber, please log in so you can continue to enjoy unlimited access to stories and archives. Subscriptions start at $5 per month and may be cancelled at any time.