A Texas rabbi who was kidnapped along with three members of his congregation by an armed man demanding the release of a convicted terrorist posted on social media Sunday that he is “grateful to be alive.”

On Saturday, Rabbi Charlie Cytron-Walker was leading Shabbat services at Congregation Beth Israel in the Dallas-Fort Worth suburb of Colleyville, Texas, when a man interrupted the service and allegedly claimed he had planted bombs in the synagogue, according to law enforcement officials.

According to Matthew DeSarno, special agent in charge of the FBI’s Dallas field office, the suspect, who died in the incident when an FBI hostage rescue team breached the synagogue, was identified on Sunday as Malik Faisal Akram, 44, a British citizen. President Joe Biden said on Sunday that he was briefed on the incident by Attorney General Merrick Garland.

According to Biden, the suspect had only been in the country for a few weeks and had spent at least one night in a homeless shelter. He claimed the suspect was armed with a gun he allegedly bought on the street, but investigators found no evidence of explosives in his possession.

After-action forensics will determine who fired the fatal shot and under what conditions.

Members of Cytron-flock Walker’s watched in horror as a Facebook Live broadcast of the service turned into a life-threatening standoff that lasted 10 hours and ended with flashbangs and gunfire when an elite FBI hostage rescue team breached the temple and freed the hostages. Rabbi Charlie, as he was affectionately known by his congregation, thanked friends and strangers from across the country for “all the vigils and prayers and love and support.” He also expressed gratitude to the law enforcement officers and first responders who “cared for us.”

Cytron-Walker issued another statement Sunday afternoon, claiming that active-shooter drills and security courses he and members of his congregation had taken from the Colleyville Police Department, the FBI, and the Anti-Defamation League had likely saved his and the other hostages’ lives. He urged other Jewish congregations, religious organizations, and schools to receive similar training.

On Saturday, around 10:40 a.m., the hostage-taking began. In an interview on Sunday, Olivia Zelling and Stacey Silverman said they were both watching the Facebook Live feed when the service went from prayer to panic.

Silverman said her mind was immediately flooded with fears that she was witnessing a replay of the 2018 anti-semitic mass shooting at Pittsburgh’s Tree of Life Synagogue and the deadly 2019 shooting at the Chabad of Poway synagogue near San Diego.

While there was no footage of the hostage-taking unfolding, there was audio of the suspect apparently speaking to hostage negotiators. According to a portion of the broadcast obtained by the Fort Worth Star-Telegram, the suspect can be heard saying, “I’ve got these prisoners” and “I’m going to die” at one point.

During Akram’s alleged speech, the broadcast only showed a screen with written instructions for silent prayer and the words, “My God, protect my words from evil and my lips from deception. I will keep my mouth shut in front of those who slander me, and I will practice humility.”

While Silverman is concerned about the rise in antisemitism and attacks on Jewish communities across the country, she admits that “in the back of our minds, you know, we knew it could happen here.”

The incident’s cause is being investigated. According to DeSarno’s statement, the FBI’s Evidence Response Team was processing evidence at the synagogue on Sunday, and the bureau’s North Texas Joint Terrorism Task Force was investigating leads in the case.

According to Assistant Chief Constable Dominic Scally of the Greater Manchester Police Department in England, British counterterrorism officers are assisting their American counterparts in the investigation. Scally stated in a statement that Akram was from the Lancashire town of Blackburn, which is about 20 miles northwest of Manchester.

Authorities said it was unclear how heavily armed the hostage-taker was during the standoff. The suspect was carrying backpacks and claimed to be in possession of explosives.