"The crowd walked up to the barricades and started banging on them using rocks, sticks and even bare hands," said Sultan Zaki Al-Saud in a CNN iReport. "It sounded like thunder as the hollow barricades rang with every blow."
During his time in office, Morsy had squared off against Egypt's judiciary, the media, the police and even artists.
Egyptians are frustrated with rampant crime and a struggling economy. Unemployment remains high, food prices are rising and there are frequently electricity cuts and long fuel lines.
'The world is looking'
Morsy had remained defiant.
"The world is looking at us today," he said Wednesday in a taped statement delivered to the Arabic satellite network Al Jazeera. "We by ourselves can bypass the obstacles. We, the sons of Egypt, the sons of this country -- this is the will of the people and cannot be canceled."
Shortly after Morsy's statement aired, Al Jazeera reported its Cairo studios had been raided during a live broadcast and 28 staff members arrested. Most were later released, it said.
On Thursday, Al Jazeera's acting chief, Mostefa Souag, demanded the immediate release of the Egyptian channel's managing director, Ayman Gaballah, and Al Jazeera Arabic broadcast engineer Ahmad Hasan.
"A return to Mubarak-era practices of mass arrests and politically motivated imprisonment of Muslim Brotherhood leaders will have the worst possible effect on Egypt's political future," said Human Rights Watch, the U.S.-based advocacy group.
Concerns of a backlash
Some observers warned of an extremist backlash.
"The major lesson that Islamists in the Middle East are likely to learn from this episode is that they will not be allowed to exercise power, no matter how many compromises they make in both the domestic and foreign policy arenas," said Mohammed Ayoob, Michigan State University professor emeritus of international relations.
"This is likely to push a substantial portion of mainstream Islamists into the arms of the extremists who reject democracy and ideological compromise," Ayoob wrote in a CNN.com opinion piece.
President Barack Obama said the United States was "deeply concerned" by Morsy's removal and the suspension of the constitution.
He called upon the military to hand over power to "a democratically elected civilian government" but did not say it needed to be Morsy's.
At least three high-level conversations took place between U.S. military officials and their Egyptian counterparts in the past week, Pentagon officials said Thursday.
The president's national security team that has been in touch with Egyptian officials and regional allies urged a "quick and responsible" return to a democratically elected government, the White House said Thursday.
Washington has supplied Egypt's military with tens of billions of dollars in support and equipment for more than 30 years. Under U.S. law, that support could be cut off after a coup.
Obama said he had ordered "the relevant departments and agencies" to study how the change in power would affect U.S. aid.
The German government was more blunt in its assessment.
"This is a heavy setback for democracy in Egypt," German Foreign Minister Guido Westerwelle said. "It is very urgent for Egypt to return to constitutional order as soon as possible."