The fate of many of the Notre Dame's treasures is still unknown after the huge fire which ripped through the 850-year-old cathedral on Monday. Experts are today entering the wreckage of the Paris landmark to find which of the precious artworks and religious relics have been saved. The mayor of Paris said that one of the most irreplaceable items - the crown of thorns reputed to have been worn by Jesus at his crucifixion - was safe last night. But there are fears for the church's 13th-century stained glass windows and its magnificent organ, while the wooden roof and ornate spire have gone. Safe: Crown of thorns One of the cathedral's most precious objects, a relic purported to be the crown of thorns worn by Jesus Christ on the cross, was whisked away to a secure facility. Reports in France stated that the chaplain of the Paris fire brigade had gone inside with the firefighters to save the crown. Experts said the irreplaceable item had been kept in a 'very safe place'. The 'Crown of Thorns' said to have been worn by Jesus Christ at his crucifixion, pictured in Notre Dame cathedral, has been saved from Monday night's blaze Safe: Tunic of St Louis A 13th-century linen tunic which is thought to have belonged to King Louis IX - canonised as St Louis - was also made safe, the mayor of Paris said. In his 44-year reign Louis took part in the Crusades and established early principles of justice such as the presumption of innocence. He was proclaimed a saint in 1297 - the only French monarch to receive the honour - and was responsible for acquiring the Crown of Thorns. Safe: Statues airlifted from the roof Renovation was already taking place at the cathedral - which may have been linked to the fire. As part of that work, 16 copper statues were airlifted from near the now-destroyed spire just days before the blaze. Some copper statues, including this sculpture of St John, were removed from the top of Notre Dame just days before the blaze hit the Paris cathedral Apparently safe: Descent from the Cross This 1723 statue by Nicolas Coustou sits on the cathedral's high altar. It shows Jesus being taken down from the cross after his crucifixion. Initial pictures showed the cross still standing with part of the sculpture visible, although it was surrounded by smoke and debris. The cross and statue on Notre Dame's altar - sculpted by Nicolas Coustou in 1723 - were apparently intact after the blaze but surrounded by smoke and debris Apparently safe: Cathedral bells Despite fire racing through Notre Dame's roof, firefighters were able to prevent the blaze consuming the cathedral's main structure, including its two bell towers. The bells that have rung out at key moments in France's history were thought to be safe. Emmanuel, the largest bell, was lifted into the south tower in 1685 and weighs over 23 tonnes. Victor Hugo's Hunchback of Notre Dame, Quasimodo, was the cathedral's bell-ringer. The two cathedral bell towers were still standing this morning with the fire extinguished, offering some hope to Parisians who feared the entire building would collapse Unknown: North, West and South Rose Windows The magnificent stained-glass artworks in the cathedral date back to the 13th century. A French journalist at the scene last night https://twitter.com/Valdiguie/status/1117925148227665921 the north window appeared to be safe with no sign of broken glass although firefighters remained concerned. There have been conflicting reports on the fate of the other two windows but one picture this morning appeared to show the south one largely intact. Architecture professor Julio Bermudez said the stained glass windows were 'really irreplaceable'. This picture appeared to show the North Rose Window intact on Tuesday morning but the fate of the other stained-glass masterpieces was still unclear Apparently safe: Grand Organ Paris' deputy mayor said Notre Dame's organ, one of the biggest and most famous in the world, remains intact after the fire. The organ, which has its beginnings in 1401, was refurbished in 2013 when the cathedral celebrated its 850th birthday. Each of the nearly 8,000 pipes, some of which date back to the 18th century, was individually cleaned and returned to its place while nine new, gargantuan bells replaced the 19th century ones. The archbishop of Paris said on Tuesday that it may have been damaged but did not appear to have been destroyed. The pipes of the cathedral's Grand Organ - which were cleaned in 2013 - stand under one of the stained glass windows. It is unclear whether the organ was damaged in the fire Unknown: Choir screen An ornate division separates the congregation from where the clergy would be seated. It features 14th-century sculptures by Pierre de Chelle, Jean Ravy and Jean Le Bouteiller. Unknown: True Cross and Holy Nails Another of the cathedral's relics is a purported piece of the True Cross - the very instrument on which Jesus was crucified in the first century AD. The collection also includes a nail which is said to be from the cross. It was unclear on Tuesday morning whether these had been saved along with the Crown of Thorns. A reputed piece of the True Cross - the very instrument on which Jesus was crucified - is one of the relics in Notre Dame's collection Unknown: Madonna and Child statue The 14th-century, life-sized statue of the Virgin Mary and baby Jesus is also known, like the cathedral itself, as Notre Dame or Our Lady. It stands near the Descent from the Cross sculpture which apparently escaped destruction but its own fate is still unclear. Unknown: The Mays paintings A series of paintings made in the 17th and early 18th century, these artworks were offered to the cathedral in May every year. They include images of the conversion of St Paul on the road to Damascus and of the crucifixion of St Peter. Unknown: Painting of Thomas Aquinas A painting titled Saint Thomas Aquinas - Fountain of Wisdom - is believed to date from 1648. It shows the Italian theologian, who heavily influenced Western philosophy, and was painted by Antoine Nicolas. A statue of the Virgin Mary holding an infant Jesus Christ, sculpted in the 14th century, is one of the treasures still not accounted for in Notre Dame Unknown: Statue of St Denis This sculpture begun in 1853 depicts St Denis, the patron saint of the city of Paris and a Christian martyr from the 3rd century AD. The statue in Notre Dame shows him holding his severed head after he was executed, but its fate today is not yet known. Unknown: The Visitation painting Jean Jouvenet's 1716 painting shows the Virgin Mary raising her head and arms towards Heavan, with her relative Elizabeth nearby. It is on the western wall of the Saint-Guillaume chapel within the cathedral but its current status is unclear. Destroyed: Irreplaceable wooden roof The cathedral's wooden roof - built with beams made more than 800 years ago from ancient forests - was burned to ashes in the fire. A French cultural heritage expert has said that France no longer has trees big enough to replace them. He said the restoration work will have to use new technologies to rebuild the roof. The wooden roof was destroyed in the smoke and flames of the 12th-century cathedral. Experts said France no longer had the trees to replace it in the same way Destroyed: 19th-century spire Parisians watched in horror last night as the spire burned and then collapsed in the intense heat of the blaze. The 13th-century spire was dismantled during the French Revolution and later rebuilt in the 1860s. The spire of the Notre Dame collapses last night. This one was created in the 19th century after the original medieval spire was destroyed during the French Revolution All rights reserved for this news site dailymail and under his responsibility