Long Beach Fire Department members responded at approximately 9:21 p.m., the department said Thursday. On Wednesday (local time), a 48-foot (about 14.6 meter) long boat was reported to have crashed at the Alamitos Bay pier, Xinhua news agency reported.

"In total, 11 patients were involved in this incident. Unfortunately, one was confirmed dead," the department said, adding that the remaining ten patients were taken to local area hospitals. Three patients were identified in critical condition.

The victim, described as only 40-50 years old, was pronounced dead on the boat, local KTLA television station reported.

The exact cause of the pleasure boat hitting the rocks is unclear, but officials told local media that speed was likely a factor.