The weather is damp but the atmosphere is electric for the 119th running of the Boston Marathon.
Along the route, well-wishers have drawn "Boston Strong" in chalk on the pavement. Spectators braving the wind and drizzle are lining the 26.2-mile course, banging cowbells and blowing air horns to support the runners as the elite women crest Heartbreak Hill.
The theme music from the "Rocky" movies has been playing and many on the sideline have been waving American flags.
One house on the course had a large banner hanging that read: "Believe in Boston."
Uniformed National Guard troops have been mingling with the crowds to help secure Monday's race.
American Tatyana McFadden has won her third straight women's wheelchair race at the Boston Marathon.
McFadden rolled down Boylston Street to finish in an unofficial 1 hour, 52 minutes, 54 seconds.
McFadden wore a singlet in memory of Martin Richard, the 8-year-old boy who was killed in the 2013 finish line bombing.
McFadden, 25, is a four-time Paralympian and also the reigning champion of the Chicago, New York City and London marathons. She also finished second in the 1 kilometer Nordic skiing sprint in the 2014 Paralympics.
The fastest man in the Boston Marathon field, Kenya's Patrick Makau, has dropped out.
Makau ended his race shortly after the 5-kilometer checkpoint. It wasn't clear why he dropped out.
The Kenyan's personal best of 2 hours, 3 minutes, 38 seconds made him one of the biggest threats to defending champion Meb Keflezighi's hopes of repeating Monday.
Marcel Hug of Switzerland won the men's wheelchair race.
It took him 1:29:53 for his first Boston win. The 28-year-old finished fourth last year.
Hug deprived Ernst Van Dyk of his 11th Boston Marathon victory. He's already the most decorated Boston competitor with 10 titles.
Defending champion Meb Keflezighi and the other elite men have started the Boston Marathon.
Keflezighi's victory last year, the first after the deadly bombings, was the first by an American since 1983.
His fastest rival in Monday's 119th edition of the race is Kenya's Patrick Makau, whose personal best is 2 hours, 3 minutes, 38 seconds.
Lelisa Desisa, who won the 2013 Boston and then donated his winner's medal to the city after the bombings near the finish, is one of four Ethiopians who have completed a marathon in under 2:05.
The 2012 winner, Wesley Korir, also is in the field.
Making his Boston debut is American Dathan Ritzenhein, who ran 2:07:47 in Chicago in 2012.
The first of three waves of 10,000 runners each went off with the elite men.
The elite women are off in the Boston Marathon, and Americans are pinning their hopes on Shalane Flanagan to break a 30-year drought for the olive wreath.
Flanagan was seventh last year and fourth in 2013. She was third in last year's Berlin Marathon in a personal best of 2 hours, 21 minutes, 14 seconds.
American Desiree Linden also is a threat. Linden was 10th last year and missed winning in 2011 by two seconds.
Both face formidable competition Monday. The women's field includes two former Boston champions — Sharon Cherop from 2012 and fellow Kenyan Caroline Kilel from 2011. Also running is last year's runner-up, Buzunesh Deba of Ethiopia.
The last U.S. women's victory was by Lisa Weidenbach in 1985.
Rain has started falling at the Boston Marathon starting line, and forecasters warn that it will be a soggy race for the 30,000 runners and 1 million spectators.
David Parkinson of New York City is running his sixth consecutive Boston. The 29-year-old was sheltering under a tent, sitting on trash bags and swaddled in blankets to keep warm.
In a sign of enhanced security two years after terrorist bombings killed three spectators and wounded more than 260 others, runners and others were being scanned with a metal-detecting wand at the start in Hopkinton, Massachusetts.
Monday's 119th running of the Boston Marathon began with a special start for mobility-impaired participants. Push rim wheelchairs start at 9:17 a.m., and the elite women set off at 9:32 a.m. The elite men and the first of three waves of runners start at 10 a.m.
Boston Marathon runners are arriving at the athletes village in Hopkinton, Massachusetts, and security is tight for the 119th running of the venerable race.
Police are patrolling the area with bomb-sniffing dogs. Authorities say more than 3,000 officers — uniformed and undercover — have been deployed for Monday's marathon.
It's the second edition since terrorist bombs killed three people and wounded more than 260 others at the finish line in 2013.
Among those waiting for the start of the 26.2-mile race was Jessica Colindres, a Guatemala native who lives in Massachusetts and was stopped less than a mile from the finish in 2013 when police closed the course.
She says her goal is a "happy, healthy and safe" race.