The investigation into the cause of last Friday’s bleacher collapse at Trumbull High remains active.

The small bleacher, which had about 30-35 students on it, collapsed while Trumbull was playing Fairfield Warde in a CIAC quarterfinal baseball game.

“The Board of Ed. has called in engineers,” Fire Marshal Megan Murphy said Tuesday. “Witness statements are also being reviewed at this time.”

Murphy said there is no firm date for when the investigation will be complete.

One girl was transported to the hospital, following the collapse. Murphy said she heard the student had possibly fractured ribs. Another student was taken to a doctor by her parents and three others had minor injuries.

A time-out was called immediately after the collapse, but the game resumed quickly, as school officials, police and emergency crews rushed to the area. Trumbull EMS, Police, Trumbull Center Fire, Long Hill Fire and the Trumbull Fire Marshal responded to the scene. Fire units helped secure the scene and assist EMS.

HANRadio.com was broadcasting live from the game when the collapse occurred, just before 5 p.m. Friday. In audio from the moment the bleachers collapsed, a loud metal sound can be heard.

“We heard something crash and sure enough, it was the student section,” HAN’s Rob Adams says on the clip. “So far I’m seeing nothing but laughter but now I’m seeing some concern down that left field line.

Adams, who was broadcasting with Paul Silverfarb, said it appeared a part of the bleachers just peeled away. Listen to the clip here.