The producers of Broadway‘s The Book of Mormon and the owner of the Eugene O’Neill Theatre are assessing today’s fire damage to the venue and will announce performance schedule disruptions “as soon as possible.”

“The production team for The Book of Mormon, in consultation with theatre owner ATG Entertainment, will take time to assess the extent of the damage, and any news of disruption to performances will be announced as soon as possible,” producers said in the latest updated statement on today’s three-alarm fire at the venue.

No performances were scheduled for today – the long-running show is dark on Mondays – but it seems likely that the schedule for the remainder of this week, at least, will be impacted. Fire officials described the damage sustained by the building as “substantial.”

The Book of Mormon is typically one of Broadway’s best-grossing productions, with the most recent figures for the week ending April 26 showing a gross of $752,688 and attendance often at the 90% of capacity level. The Tony-winning musical comedy began previews at the O’Neill on February 24, 2011, opening March 24 that year.

The fire broke out sometime around 10 a.m. today and the venue on West 49th Street was quickly cleared of all employees and visitors.

According to the New York Fire Department, no cause has been determined, but the fire apparently broke out in an electrical room. The NYFD says one firefighter was injured, and that the building sustained substantial damage and will be out of service pending repairs.

A 3-alarm fire signifies a “significant fire,” often involving large building and multiple floors, with a significant presence of fire apparatus and firefighters on the scene.

More than 60 FDNY units and nearly 200 first responders are reportedly at the scene.

The venue opened in 1925 and has been known previously as the Forrest Theatre and the Coronet Theatre. It was renamed for the Long Day’s Journey Into Night playwright in 1959, and has hosted such productions as The Odd Couple, M. Butterfly, The Fully Monty and many others. Owned by ATG Entertainment, the interior of the 1,108-seat venue is a New York City designated landmark.