HAYWARD -- Commuters were scrambling Wednesday morning after a fatality on BART tracks shut down trains south of San Leandro for more than 12 hours.

The South Hayward, Union City and Fremont stations all were closed after the incident, which occurred near the South Hayward station about 11:30 p.m. Tuesday, BART spokesman Jim Allison said.

The person who died was described as male but his identity was not released. The person was not an employee and an initial investigation by police showed no signs of foul play, Allison said.

The tracks reopened about 7:50 a.m., and residual delays of 15 to 20 minutes lasted through the morning. BART police completed their investigation about 6:30 a.m., and BART's operations department then inspected the tracks, Allison said.

The shutdown drew riders to the Bay Fair station in San Leandro, where commuters had been told to catch Richmond and San Francisco-bound trains. AC Transit buses were an option, though BART was unable to provide a bus bridge.

When trains arrived shortly after 8 a.m. Wednesday at the South Hayward station, about 200 passengers spilled out, some running to their jobs.

"I hope," said Renee Washington, 50, "that my boss will understand how late I am."

Allison said AC Transit was asked but not able to provide a bus bridge.

BART officials issued an advisory at 4:15 a.m. that service was down, urging passengers to catch trains at the Bay Fair station or use alternative transportation.

AC Transit driver James Thomas, 53, said he received a phone call from his daughter while stationed outside the South Hayward station about 9 a.m. and said she told him it took 1½ hours to reach her destination after leaving from the Pittsburg-Bay Point station.

Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH. Contact Natalie Neysa Alund at 510-293-2469 and follow her at Twitter.com/nataliealund.