A 66-year-old man has died after lifeguards found him floating unconscious in waters off Kaimana Beach in Waikiki Sunday.

The Honolulu Medical Examiner’s Office identified him as Timothy J. Lui-Kwan of Honolulu.

Lui-Kwan was a veteran Honolulu attorney who defended the University of Hawaii at Hilo over the Thirty Meter Telescope project and was a partner in the Honolulu law office of Carlsmith Ball.

Police said Lui-Kwan was swimming with his family at about noon and was later found unresponsive. Lifeguards brought him to shore, and paramedics transported him in critical condition to a hospital where he died.