A former member of the Official IRA collapsed as he gave evidence at the Saville Tribunal in Derry today.
An ambulance was called and the hearing at The Guildhall adjourned until tomorrow.
The witness admitted firing two shots at British soldiers after members of the Parachute Regiment had fired at civilians, killing 13 and wounding 13 others.
The man - identified as Official IRA man 4 - also said he left the area when he realised he would make no impact against the advancing troops.