This is how we spend Sunday mornings in San Fran #baytobreakers pic.twitter.com/2RRySFvisa — Charlene Li (@charleneli) May 17, 2015

SFPD trying to clear race route. "The race is over!" #mapit pic.twitter.com/WsRmJnUPKE — Cbarnard (@CornellBarnard) May 17, 2015

Mario and a giraffe are on BART. Yep, it's Bay to Breakers time. #BaytoBreakers pic.twitter.com/pyCHwdsuzN — Nicole Lee (@nicole) May 17, 2015

Two crayolas walk into a bar. I mean, into a McDonalds and order breakfast... #BaytoBreakers pic.twitter.com/1tMSTgcAJD — Mónica Quiroz (@monica) May 17, 2015

With thousands taking @Caltrain_News to #BaytoBreakers today, SMCSheriff helps keeps the peace amongst the fun! pic.twitter.com/eSW6iUHIn7 — San Mateo County S.O (@SMCSheriff) May 17, 2015

Live pic of runners at the start of #BaytoBreakers pic.twitter.com/hJXPF4d4Ow — Frances Dinglasan (@francesabc7) May 17, 2015

This year there will be < 1,000 porta-potties along the 7 1/2 mile race. #BaytoBreakers Leave the petunias alone! pic.twitter.com/wf3wK3fsJ6 — Lyanne Melendez (@LyanneMelendez) May 17, 2015

Look what some runners are wearing tomorrow during #BaytoBreakers Cool Headbands @SPARKLYSOULINC pic.twitter.com/ECFoagGCSJ — Lyanne Melendez (@LyanneMelendez) May 16, 2015

Runners on your mark....Getting ready for #BaytoBreakers. Picking up official t-shirt for event. #runners pic.twitter.com/QQeptz0Izt — Lyanne Melendez (@LyanneMelendez) May 16, 2015

SAN FRANCISCO (KGO) -- Thousands of runners took part in one of the most iconic races in the world -- San Francisco's Bay to Breakers. Originally called the Cross City Race, it's a tradition more than a century old.Police arrested 11 people during the footrace. Officers arrested five people on suspicion of felonies, three people on suspicion of misdemeanors and three people on suspicion of being drunk in public.Medical crews responded to 14 medical calls and police said 10 people were treated at sobering centers.The race got underway at 8 a.m. at Beale and Howard streets with 50,000 runners taking to the race course through the heart of San Francisco.Isaac Mukandi Mwangi of Kenya finished the race first with a time of 35:25. He was followed by Bashir Abfi with a time of 35:27 and Julius Kieter with a time of 35:30.Jane Kibii, winner of the race's female division, finished with a time of 40:04. She was followed by Nazret Weldu with a time of 40:46 and Susan Jerotich with a time of 40:47.The quirky race featured lots of impressive costumes from a dinosaur to WonderWoman to a duo dressed as jellyfish. And some, as per the race's unwritten tradition, opted for no clothes at all.Many runners say the Bay to Breakers experience is truly one-of-a-kind."It's really, really fun," said runner Chandler Kent. "Right at the start of the race I was running with a couple guys and they pulled away from me. But with about a mile and a half left I got to roll back up on them and we had a good duel going into he last mile."Not everyone likes the Bay to Breakers. Some neighbors are glad it only happens once a year. "You have a lot of people so drunk, they don't have respect for others," Jeremy Pachter said.Pachter stood watch on his front stairs discouraging public urination.Ahead of the big race, police advised participants to have fun but leave the alcohol at home. They warned runners that if they were spotted drinking on the course, the alcohol would be taken away from them.Extra security was on hand as well. Police wanted to make sure the race was safe and fun. This year, extra port-a-potties were on hand. About 1,100 of were spread throughout the course.The race began at 8 a.m. near the Embarcadero and finished at Ocean Beach.