Two people are dead and one more person is critically injured after a shooter opened fire during Sunday morning service at a church near Fort Worth, Texas.

Two congregants, both volunteer members of the church’s security team, drew their weapons and confronted the gunman, fatally shooting him and saving an “untold number of lives” at West Freeway Church of Christ in White Settlement, a town of about 17,000 people near Fort Worth.

Their actions, described as “heroic” by the Texas Department of Public Safety, brought a quick end to an attack that remained under investigation on Sunday night. Authorities have not provided information about a possible motive.

City Police Chief J.P. Bevering said the shooter entered West Freeway Church of Christ and sat down in the sanctuary just before 11 a.m. CT Sunday. He then stood, pulled out a shotgun and shot two parishioners, Bevering said.

The shooting took place at about 11:50 (17:50 GMT) on Sunday, during a morning service that was being livestreamed on social media.

Video footage showed the gunman stand up from a pew and speak to a man nearby, who gestured at another parishioner. The gunman then fired at the man he gestured towards.

The gunman fired again, at the man he had spoken to, before a member of the congregation acting as a security guard returned fire with a handgun, immediately felling the attacker.

Several other parishioners also produced handguns and trained them on the attacker. It was not clear from the video footage whether any of the other armed parishioners fired shots.

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