() A nihilistic ideology may have driven a 25-year-old man to detonate a bomb outside a southern California fertility clinic, killing himself and causing wide destruction in the process.

Published reports indicate Guy Edward Bartkus considered himself a “pro-mortalist,” someone who believes it’s better to die than to continue existing and that it’s wrong to bring new sentient life into the world. He is suspected of detonating a powerful explosive Saturday targeting American Reproductive Centers in Palm Springs, where in vitro fertilization (IVF) services are offered.

“It’s one of the strangest, I guess you’d say, single-issue domestic terrorist movements I’ve ever seen,” national security expert Hal Kempfer, a retired Marine intelligence officer, told “ Prime” on Sunday.

Tracy Walder, a national security contributor and former federal agent, said Bartkus’ supposed views contrast with the “pro-life” ideology associated with strikes against abortion clinics.

“This essentially is the idea that it is more humane to kill humanity to prevent future suffering,” Walder said of Bartkus’ motives. “He believes that he is doing the humane thing.”

Four people were injured in the blast but are no longer in the hospital. Offices within the fertility clinic were damaged, but no embryos were affected, operators of the facility told The Associated Press.

The FBI said the blast, with a wide debris field, was the largest bombing ever in Southern California. It wasn’t immediately known how Bartkus constructed the explosive device or where he acquired materials. One former FBI agent and bomb technician said it may not have been that difficult.

“The genie is out of the bottle. If you go on the Internet, you can find very specific instructions on how to build various types of devices using different types of explosives,” Jim Maxwell told . “Someone who has the ability to read and a high school education and can follow instructions could build a very significant device.”