A 30-year-old man died Saturday after completing the Brooklyn Half Marathon in New York City.

According to WABC, the unidentified runner collapsed at around 9 a.m. near the finish line of the 13.1 mile race. Authorities say he was immediately transported to Coney Island Hospital, but was pronounced dead shortly after. The medical examiner has not determined the runner’s cause of death, but police say they believe he suffered cardiac arrest.

“We are deeply saddened by the passing of a participant following the 2022 RBC Brooklyn Half,” New York Road Runners wrote in a statement. “Our thoughts and sympathies are with the runner’s family and those close to them [...] The health and safety of our runners, volunteers, partners, and staff remain the top priority for NYRR. In coordination and consultation with the city agency partners and weather experts, NYRR was closely monitoring weather conditions leading up to and during the race. Throughout the race, weather temperatures ranged from the low 60s to high 70s.”

The National Weather Service of New York issued a heat advisory Saturday, as temperatures were expected to reach up to 30 degrees above average. It’s unclear whether the heat played a role in the man’s death.

Dense fog advisories remain in effect this morning for all locations through at least 9am. Once the fog dissipates, temps will warm into the 80s and 90s. As a result, a heat advisory is in effect for parts of our area. Dont forget to visit https://t.co/0cofXEqkfH for the details. pic.twitter.com/lN30mW5UQO

— NWS New York NY (@NWSNewYorkNY) May 21, 2022

Marathon organizers also confirmed 16 runners were hospitalized after participating in the annual event. Eight of them had non-life threatening injuries, four had minor injuries, and five are said to be in serious condition. 

Saturday marked the first time in three years that the Brooklyn Half Marathon reached full capacity. Officials say more than 22,000 people ran the race, which began at 7 a.m. in Prospect Park and concluded at the Coney Island boardwalk.