John Carpenter's The Fog

As the Californian coastal town of Antonio Bay is about to celebrate its 100th anniversary, paranormal activity begins to occur at the stroke of midnight. Town priest Father Malone is in his church when a piece of masonry falls from the wall, revealing a cavity containing an old journal, his grandfather's diary from a century ago. It reveals that in 1880, six of the founders of Antonio Bay (including Malone's grandfather) deliberately sank and plundered a clipper ship named the Elizabeth Dane. The ship was owned by Blake, a wealthy man with leprosy who wanted to establish a leper colony nearby. Gold from the ship was used to build Antonio Bay and its church.
Meanwhile, three fishermen are out at sea when a strange, glowing fog envelops their trawler. The fog brings with it the Elizabeth Dane, carrying the vengeful revenants of Blake and his crew who kill the fishermen. Meanwhile, town resident Nick Castle is driving home and picks up a young hitchhiker named Elizabeth Solley. As they drive towards town, all the truck's windows inexplicably shatter.
The following morning, local radio DJ Stevie Wayne is given a piece of driftwood inscribed with the word "DANE" that was found on the beach by her young son Andy. Intrigued, Stevie takes it with her to the lighthouse where she broadcasts her radio show. She sets the wood down next to a tape player that is playing, but the wood inexplicably begins to seep water causing the tape player to short out. A mysterious man's voice emerges from the tape player swearing revenge, and the words "6 must die" appear on the wood before it bursts into flames. Stevie quickly extinguishes the fire, but then sees that the wood once again reads "DANE" and the tape player begins working normally again.
After locating the missing trawler, Nick and Elizabeth find the corpse of Dick Baxter with his eyes gouged out. The other two fishermen are missing, one of whom is the husband of Kathy Williams, who is overseeing the town's centennial celebrations. While Elizabeth is alone in the autopsy room, Baxter's corpse rises from the autopsy table and approaches her. As Elizabeth screams, Nick and coroner Dr. Phibes rush back into the room where they see the corpse lifeless again on the floor, upon which it has carved the number 3. That evening, as the town's celebrations begin, local weatherman Dan calls Stevie at the radio station to tell her that another fog bank has appeared and is moving towards town. As they are talking, the fog gathers outside the weather station and Dan hears a knock at the door. He answers it and is slaughtered by the revenants as Stevie listens in horror. As Stevie proceeds with her radio show, the fog starts moving inland, disrupting the town's telephone and power lines. Using a back-up generator, Stevie begs her listeners to go to her house and save her son when she sees the fog closing in from her lighthouse vantage point. As the fog envelops Stevie's house, the revenants kill her sonâs babysitter, Mrs. Kobritz. They then pursue Andy, but Nick arrives just in time to rescue him.
Stevie advises everyone to head to the town's church. Once inside, Nick, Elizabeth, Andy, Kathy, her assistant Sandy, and Father Malone take refuge in a back room as the fog arrives outside. Inside the room, they locate a gold cross in the wall cavity which is made from the stolen gold. As the revenants begin their attack, Malone takes the gold cross out into the chapel. Knowing that they have returned to take six lives in lieu of the six original conspirators who led them to their deaths, Malone offers the gold and himself to Blake to spare the others. At the lighthouse, more revenants attack Stevie, trapping her on the roof. Inside the church, Blake seizes the gold cross, which begins to glow. Nick pulls Malone away from the cross seconds before it disappears in a blinding flash of light along with Blake and his crew. The revenants at the lighthouse also disappear, and the fog vanishes. Later that night, Malone is alone in the church pondering why Blake did not kill him and thus take six lives. The fog then reappears inside the church along with the revenants, and Blake decapitates Malone.

Question: What anniversary is Antonio Bay celebrating?
Answer: 100th.