By SARAH RAZA and ERIC TUCKER

A 25-year-old man the FBI believes was responsible for an explosion that ripped through a Southern California fertility clinic left behind “anti-pro-life” writings before carrying out an attack investigators are calling an act of terrorism, authorities said Sunday.

Guy Edward Bartkus of Twentynine Palms, California, was identified by the FBI as the suspect in the apparent car bomb detonation Saturday that damaged the clinic in the upscale city of Palm Springs in the desert east of Los Angeles.

Investigators believe Barktus died in the blast, which a senior FBI official called possibly the “largest bombing scene that we’ve had in Southern California.” A body was found near a charred vehicle outside the clinic.

Bartkus attempted to livestream the explosion and left behind writings that communicated “nihilistic ideations” that were still being examined to determine his state of mind, said Akil Davis, the assistant director in charge of the FBI’s Los Angeles field office. U.S. Attorney Bilal “Bill” Essayli, the top federal prosecutor in the area, called the writings “anti-pro-life.”

The Associated Press reported Saturday night that those writings professed a sentiment that the world should not be populated.

“This was a targeted attack against the IVF facility,” Davis said Sunday. “Make no mistake: we are treating this, as I said yesterday, as an intentional act of terrorism.”

The bombing injured four other people, though Davis said all embryos at the facility were saved.

“Good guys one, bad guys zero,” he said.

Authorities were executing a search warrant in Twentynine Palms, a city of 28,000 residents about 50 miles (80 km) northeast of Palm Springs, as part of the investigation.

The suspect posted writings online and attempted to record the explosion, though authorities said the video failed to upload. An official who was not authorized to discuss details of the attack spoke on condition of anonymity to the AP.

The blast gutted the single-story American Reproductive Centers clinic, though a doctor said its staff members were safe.

“Thank God today happened to be a day that we have no patients,” Dr. Maher Abdallah, who leads the clinic, told the AP in a phone interview Saturday.

Associated Press writer Christopher Weber contributed from Los Angeles.