Two vistors to the Tate Modern have fallen into the hole which forms the centrepiece of the new installation in the Turbine Hall.
The pair, who were at a private viewing of Doris Salcedo's Shibboleth 2007, were not seriously injured.
The London museum said there were no incidents when it was opened to the public for the first time on Tuesday.
A Tate spokeswoman added there were no plans to place barriers around the 167-metre long crack at this stage.
"Tate staff are monitoring the space carefully to ensure the safety of our visitors and there are measures in place.
"We have a lot of experience handling complex installations and visitor safety," she added.
The hole will remain at Tate Modern for the next six months
The two visitors to the installation - which has been informally renamed "Doris's Crack", are said to have lost their footing before stepping into the fissure.
They were attended to by security staff trained in first aid.
Some 12,000 people viewed the installation on the first day of public viewing.
Colombian artist Salcedo said the work - on display to the public until April next year - symbolised racial hatred and division in society.
Salcedo claims the work took her over a year to make, and apparently spent the past five weeks installing it in the Tate, but would not reveal how it had been achieved.
Tate Modern director Nicholas Serota has said the work is not an optical illusion, but is a sculpture created in a "painstaking, meticulous way".