ORLANDO, Fla. - Church bells will toll throughout the Orlando area as residents reflect on the 49 patrons killed during a massacre at the gay nightclub Pulse in the worst mass shooting in recent U.S. history.

  

Starting in the wee hours Monday, and continuing almost 24 hours later, survivors, victims' families, city officials and central Florida residents will remember the victims with four services.

  

The first service is closed to the public, and it's being held at the nightclub for survivors, local officials and club employees. It will overlap with the exact time gunman Omar Mateen began firing shots a little after 2 a.m. on June 12, 2016.

  

It is followed by a mid-day service at the nightclub, and an evening gathering in downtown Orlando.

  

A final late-night service is being held at the nightclub.