A 36-year-old man died while running the London Marathon on Sunday, according to the organizers the following day.

He apparently collapsed at approximately 38 kilometres into the race.

The man received immediate medical treatment and an ambulance arrived within three minutes, however, he died in a London hospital.

The organizers expressed their sincere condolences to the man’s friends and family, according to the Associated Press.

The cause of death has yet to be established and will be established through ongoing medical tests.

Organizers also said the family requested privacy, adding “no further details will be released in accordance with their wishes.”

The man was from southeast England.

More than 40,000 participants took in the race. Kenyan Amos Kipruto won in the time of 2:04:39, while Ethiopian Yalemzerf Yehualaw was the fastest woman in 2:17.25.