Distributed Acoustic Sensing (DAS) fiber deployed in the Bedretto Underground Laboratory (BULGG) in 7 boreholes, totaling 4.5 km of fiber, used in the IRIS initiative to collect global DAS data in February of 2023. Data is provided for earthquakes >M5.0 and for one day of ambient noise, using 10 m channel spacing and 100 Hz sampling. For further information see readme.