Visitors stranded at Osaka expo overnight after subway outage causes chaos

A power failure hit the Osaka Metro's Chuo Line, which is the only direct train link from the city center to the expo site on Yumeshima, the artificial island that hosts the expo.

Train services were halted at around 9:30 p.m. Wednesday -- 30 minutes before the expo usually closes -- and the line was only back to full operation early the next morning.

About 30,000 people were inside the venue as of 9:30 p.m. Wednesday, according to expo organizers. While the exact number of those affected is unclear, many visitors and expo staff were believed to have stayed overnight.

A total of 36 people were taken to hospitals by Thursday morning due to suspected heatstroke or other ailments, but none of the cases were serious, local authorities said.

"We are sorry that many people had to go through a tough time," a senior official of the Japan Association for the 2025 World Exposition told a press conference Thursday.

Osaka Metro Co. also apologized during a separate press conference, blaming the outage on an issue with the powered rail, known as the "third rail," alongside the tracks.

The situation was resolved after workers removed a cover over wires connecting the third rail. Iron powder or other substances on the cover may have caused a short circuit.

The problem initially led the subway operator to halt services from Yumeshima Station, which gives direct access to the eastern gate of the expo venue.

Services between Yumeshima and the next station, Cosmosquare, resumed at around 10:10 p.m., but Yumeshima was overwhelmed with people trying to leave and access via the station was temporarily restricted.

Visitors were encouraged to use buses and other transport services instead.

After the subway malfunction, expo visitors planning to exit via the eastern gate were asked to remain inside the site. People were seen sitting in rows beneath the expo's giant wooden structure, known as the Grand Ring, as midnight approached.

Multiple pavilions were made available late at night as shelters for those who were stranded.

Koichiro Ishihara, a 45-year-old from Osaka, said he spent the night on an artificial lawn by the Electric Power Pavilion near the eastern gate with his 6-year-old and 3-year-old daughters.

"Heading home in the crowd with small children wasn't realistic," he said, while noting that they were lucky the weather was not bad.

Takashi Yamaguchi, 69, and his wife Yoshiko, from Nara Prefecture, complained of being in pain after sleeping for several hours on a bench inside one of the expo buildings.

They said they did not know where to wait until an announcement was made after midnight informing patrons of areas that were available.

Expo organizers decided to delay the opening time on Thursday by one hour to 10 a.m. following the night of chaos, but they eventually opened the gates at 9:30 a.m. to allow the large crowd that had built up to enter.

As it is the only train service providing direct access to the expo venue, the Chuo Line is used by around 70 percent of visitors, according to its operator.

The expo is being held between April 13 and Oct. 13, with its usual opening hours from 9 a.m. to 10 p.m.

Earlier, it was reported Kazakhstan's flag had been raised in Japan in honor of the National Day at the EXPO 2025 Osaka.