People were crying, dazed and bleeding, a man lay dead and a roof peeled out after a bomb went off in a Sydney Jehovah's Witnesses hall in 1985, a judge has been told.
Anne and Gary Biddle gave evidence on Thursday at the NSW Supreme Court trial of Leonard John Warwick, who has denied a string of Sydney murders and bombings during the 1980s.
Ms Biddle described seeing ambulance officers trying to pick glass out of a girl's eyes, while her husband said he saw a friend with steel jammed into his thigh, and did not recognise a woman he knew because of her injuries.
The 71-year-old former Family Court litigant has pleaded not guilty to four murders - including the shooting deaths of his brother-in-law and a judge - and 20 other offences relating to seven events that occurred between February 1980 and July 1985.
One event involved the setting off a bomb that ripped apart the Jehovah's Witnesses Kingdom Hall at Casula on July 21, 1985, killing Graham Wyke and injuring 13 people.
The organisation had given support to Warwick's estranged wife Andrea Blanchard.
About 130 people were in the congregation in the hall, including about 25 children.
Ms Biddle testified that as the speaker began his talk, she opened her bible.
"In a blink of an eye, there was an explosion," she said.
"In the blink of an eye everything was gone, the roof - it peeled out.
"I couldn't hear anything after that. There was a surreal hissing sound and I couldn't decipher any sound."
Seats were overturned, there was dust in the hall and everybody was crying.
Mr Biddle said when the explosion went off he put his arm around his wife and pushed her down, before taking her outside and then returning to help people.
"I helped somebody cover up Graham Wyke's body. It was evident he was deceased," he said.
Both he and his wife suffered perforated ear drums.
A week earlier, he had seen blood on the carpet near a window which was broken.
The Crown has alleged that testing of the blood spots revealed the DNA was consistent with Warwick's.
The judge-alone trial is continuing before Justice Peter Garling.