SAN QUENTIN, Calif. - A death row inmate died Saturday at a hospital, while the previous day another prisoner was killed after two inmates attacked him, California officials said.

John Abel — who was sentenced to death row for killing a man in 1991 during a robbery at a bank in Orange County — died Saturday morning at a hospital, the California Department of Corrections and Rehabilitation said in a statement. He was 75.

An autopsy will be performed to determine the cause of death, according to the department, which did not reveal the name of the hospital.

Authorities do not suspect foul play, the department said.

Abel, who had previously been convicted of a string of armed robberies, was sentenced to death by an Orange County jury in 1997 for the fatal shooting Jan. 4, 1991, of a man at a bank in Tustin, the department said. The man had just withdrawn $20,000 from the bank.

Since 1978, when California reinstated capital punishment, 82 condemned inmates have died from natural causes, 27 have committed suicide, 13 were executed in California, one was executed in Missouri, one was executed in Virginia, 14 have died from other causes and seven — including Abel — are pending a cause of death, the department said. There are 728 people on California’s death row.

In a separate case, officials at the Calipatria State Prison officials are investigating the death of Joseph Martinez, 21, after two other inmates attacked him.

About 3 p.m. Friday, correctional officers arrived at the scene where two inmates attacked Martinez on the Facility C general population maximum-security yard, the department said.

Officers used chemical agents and one non-lethal 40-mm round to quell the incident.

Martinez was cut in his chest and back and was taken to the prison’s medical facility. He was then taken by ambulance to a nearby hospital, where he was pronounced dead, the department said.

Martinez had been serving a 24-year-to-life sentence for attempted first-degree murder, the department said.

Officers recovered one inmate-made weapon, the department added.

The two suspects were put in an Administrative Segregation Unit pending investigation into their involvement.