A man was trapped inside a steel-reinforced concrete jewelry vault in New York City overnight after firefighters had to abandon an attempt to rescue him for safety reasons. Fortunately, the vault was on a timer and opened on its own Wednesday morning, officials said.

The fire department was called to the midtown Manhattan building on Tuesday evening after the man became trapped while trying to access his safe deposit box, Assistant Fire Chief John Sarrocco said. The building at 580 Fifth Avenue is known as the World Diamond Tower and houses several jewelry businesses. Sarrocco did not explain how the man became trapped.

[Er … that is a really good question. How did he get into the safe without anyone noticing, and/or how did he get left in there when the vault closed? — Ed]