LOS ANGELES (AP) — An off-duty lifeguard who was critically injured during a rare lightning strike at Los Angeles' Venice Beach is said to be improving steadily.

City News Service reported Tuesday that the man, whose name was not released, remains hospitalized at Ronald Reagan UCLA Medical Center, where his condition has been upgraded from critical to fair.

Los Angeles County Supervisor Don Knabe says the man, in his 50s, is "making a good recovery."

Sunday's lightning strike killed 21-year-old college student Nick Fagnano and injured a dozen others. The lifeguard suffered the most severe injuries.

The lightning was caused when warm, subtropical air from Mexico collided with the region's cool marine layer. The result was a brief but violent thunderstorm that struck the beach where thousands were gathered on a warm summer day.