DUBAI (Reuters) – Dubai’s Emaar Properties said on Tuesday it has closed the observation deck at the world’s tallest building for maintenance, just one-month after its fanfare opening.

Burj Khalifa, formerly Burj Dubai and renamed after the president of the United Arab Emirates, opened on January 4, as the emirate struggles with billions of dollars of debt.

“Due to unexpected high traffic, the observation deck experience at the Burj Khalifa, At The Top, has been temporarily closed for maintenance and upgrade,” a Burj Khalifa spokeswoman said.

“Technical issues with the power supply are being worked on by the main and sub-contractors,” she said, adding it was not clear when the tower would reopen.

Guests who hold tickets for the highest observation deck in the world, will be offered the option to re-book or receive an immediate refund, the spokeswoman said.

Emaar Properties spent $1.5 billion (959 million pounds) on the tower since construction began in 2004, and at the peak of construction some 12,000 workers were involved.